<prompt> Tatua mlingano: 4x - 7 21.  <response>: Hakika, hivi ndivyo unavyotatua equation hiyo:Kwa kuzingatia equation 4x - 7 21, lengo ni kutenganisha x.Kwanza, ongeza 7 kwa pande zote mbili za equation:4x - 7 7 21 7Hii hurahisisha:4x 28Sasa, gawanya pande zote mbili na 4:4x 4 28 4Hii hurahisisha:x 7Kwa hivyo, suluhisho la equation 4x - 7 21 ni x 7. 