(1)
10*(15-X)=12
150-10X=12
10X=138
X=13.8
(2)
32x-7x-5x=420
(32-7-5)x=420
20x=420
x=21
(3)
1.4*5+6x=11.2
7+6x=11.2
6x=4.2
x=0.7
(1)
10*(15-X)=12
150-10X=12
10X=138
X=13.8
(2)
32x-7x-5x=420
(32-7-5)x=420
20x=420
x=21
(3)
1.4*5+6x=11.2
7+6x=11.2
6x=4.2
x=0.7