Question

10x + 12 -4x = 20 + 4x
5(x+3)+3(x+4) = 7(x+3) + 30

Answer 1

1. 6x-4x=20-12
    2x=8
    x=4

2.  5x+15+3x+12 = 7x+21+30
     8x + 27= 7x +61
     8x-7x = 61- 27
     x = 24