Luyện tập chung (tiếp theo)...
<h3 style="text-align: justify;" id="bagravei-1">Bài 1.</h3> <p style="text-align: justify;">a) 1 gấp bao nhiêu lần <mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="0" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mfrac><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c><mjx-c class="mjx-c30"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>1</mn><mn>10</mn></mfrac></math></mjx-assistive-mml></mjx-container>?</p> <p style="text-align: justify;">b) 110 gấp bao nhiêu lần <mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="1" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mfrac><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c><mjx-c class="mjx-c30"></mjx-c><mjx-c class="mjx-c30"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>1</mn><mn>100</mn></mfrac></math></mjx-assistive-mml></mjx-container>?</p> <p style="text-align: justify;">c) 1100 gấp bao nhiêu lần <mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="2" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mfrac><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c><mjx-c class="mjx-c30"></mjx-c><mjx-c class="mjx-c30"></mjx-c><mjx-c class="mjx-c30"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>1</mn><mn>1000</mn></mfrac></math></mjx-assistive-mml></mjx-container>?</p> <h3 style="text-align: justify;" id="bagravei-2">Bài 2.</h3> <p style="text-align: justify;">Tìm x</p> <p style="text-align: justify;">a)&nbsp;<mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="3" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mi class="mjx-i"><mjx-c class="mjx-c1D465 TEX-I"></mjx-c></mjx-mi><mjx-mo class="mjx-n" space="3"><mjx-c class="mjx-c2B"></mjx-c></mjx-mo><mjx-mfrac space="3"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c35"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n" space="4"><mjx-c class="mjx-c3D"></mjx-c></mjx-mo><mjx-mfrac space="4"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n"><mjx-c class="mjx-c3B"></mjx-c></mjx-mo></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>x</mi><mo>+</mo><mfrac><mn>2</mn><mn>5</mn></mfrac><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mo>;</mo></math></mjx-assistive-mml></mjx-container></p> <p style="text-align: justify;">b)&nbsp;<mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="4" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mi class="mjx-i"><mjx-c class="mjx-c1D465 TEX-I"></mjx-c></mjx-mi><mjx-mo class="mjx-n" space="3"><mjx-c class="mjx-c2212"></mjx-c></mjx-mo><mjx-mfrac space="3"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c35"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n" space="4"><mjx-c class="mjx-c3D"></mjx-c></mjx-mo><mjx-mfrac space="4"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c37"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n"><mjx-c class="mjx-c3B"></mjx-c></mjx-mo></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>x</mi><mo>-</mo><mfrac><mn>2</mn><mn>5</mn></mfrac><mo>=</mo><mfrac><mn>2</mn><mn>7</mn></mfrac><mo>;</mo></math></mjx-assistive-mml></mjx-container></p> <p style="text-align: justify;">c)&nbsp;<mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="5" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mi class="mjx-i"><mjx-c class="mjx-c1D465 TEX-I"></mjx-c></mjx-mi><mjx-mo class="mjx-n" space="3"><mjx-c class="mjx-cD7"></mjx-c></mjx-mo><mjx-mfrac space="3"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c33"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c34"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n" space="4"><mjx-c class="mjx-c3D"></mjx-c></mjx-mo><mjx-mfrac space="4"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c39"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c><mjx-c class="mjx-c30"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n"><mjx-c class="mjx-c3B"></mjx-c></mjx-mo></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>x</mi><mo>×</mo><mfrac><mn>3</mn><mn>4</mn></mfrac><mo>=</mo><mfrac><mn>9</mn><mn>20</mn></mfrac><mo>;</mo></math></mjx-assistive-mml></mjx-container></p> <p style="text-align: justify;">d)&nbsp;<mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="6" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mi class="mjx-i"><mjx-c class="mjx-c1D465 TEX-I"></mjx-c></mjx-mi><mjx-mo class="mjx-n" space="3"><mjx-c class="mjx-cF7"></mjx-c></mjx-mo><mjx-mfrac space="3"><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c37"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac><mjx-mo class="mjx-n" space="4"><mjx-c class="mjx-c3D"></mjx-c></mjx-mo><mjx-mn class="mjx-n" space="4"><mjx-c class="mjx-c31"></mjx-c><mjx-c class="mjx-c34"></mjx-c></mjx-mn><mjx-mo class="mjx-n"><mjx-c class="mjx-c2E"></mjx-c></mjx-mo></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>x</mi><mo>÷</mo><mfrac><mn>1</mn><mn>7</mn></mfrac><mo>=</mo><mn>14</mn><mo>.</mo></math></mjx-assistive-mml></mjx-container></p> <h3 style="text-align: justify;" id="bagravei-3">Bài 3.</h3> <p style="text-align: justify;">Một vòi nước chảy vào bể. Giờ đầu chảy vào được <mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="7" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mfrac><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c32"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c><mjx-c class="mjx-c35"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>2</mn><mn>15</mn></mfrac></math></mjx-assistive-mml></mjx-container> bể, giờ thứ hai chảy vào được <mjx-container class="MathJax CtxtMenu_Attached_0" jax="CHTML" tabindex="0" ctxtmenu_counter="8" style="font-size: 116.7%; position: relative;"><mjx-math class="MJX-TEX" aria-hidden="true"><mjx-mfrac><mjx-frac><mjx-num><mjx-nstrut></mjx-nstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c31"></mjx-c></mjx-mn></mjx-num><mjx-dbox><mjx-dtable><mjx-line></mjx-line><mjx-row><mjx-den><mjx-dstrut></mjx-dstrut><mjx-mn class="mjx-n" size="s"><mjx-c class="mjx-c35"></mjx-c></mjx-mn></mjx-den></mjx-row></mjx-dtable></mjx-dbox></mjx-frac></mjx-mfrac></mjx-math><mjx-assistive-mml unselectable="on" display="inline"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>1</mn><mn>5</mn></mfrac></math></mjx-assistive-mml></mjx-container> bể. Hỏi trung bình mỗi giờ vòi nước đó chảy vào được bao nhiêu phần của bể?</p> <h3 style="text-align: justify;" id="bagravei-4">Bài 4.</h3> <p style="text-align: justify;">Trước đây mua 5m vải phải trả 60 000 đồng. Hiện nay giá bán mỗi mét vải đã giảm 2000 đồng. Hỏi với 60 000 đồng, hiện nay có thể mua được bao nhiêu mét vải như thế?</p>