Simplify 
cos
sin
sin
cos
cos
+ sin
sin
cos
cos
sin
θ
θ
θ
−
θ




θ
θ




−
θ
θ
θ
θ




7 Find X and Y, if
(i)
7
0
3
0
X + Y
and X – Y
2
5
0
3




=
=








(ii)
2
3
2
2
2X + 3Y
and 3X
2Y
4
0
1
−5




=
+
=




−




8 Find X, if Y = 
3
2
1
4






 and 2X + Y = 
1
0
3
2




−

9 Find x and y, if 
1
3
0
5
6
2 0
1
2
1
8
y
x






+
=












10