3(x+5)+4x 8(7+x)-3x 9(x-7)+6x

Question

3(x+5)+4x
8(7+x)-3x
9(x-7)+6x

Answer 1

3( х + 5 ) + 4х = 7х + 15;
3х + 15 + 4х = 3х + 4х + 15 = 7х + 15;

8( 7 + х ) - 3х = 56 + 5х;
56 + 8х - 3х = 56 + 5х;

9( х - 7 ) + 6х = 15х - 63.
9х - 63 + 6х = 9х + 6х - 63 = 15х - 63.