Question

calcular el valor de x;
3.(3-x)+9=2.(x-4)+6

Answer 1

3*(3-x)+9 = 2*(x-4)+6
9 - 3x + 9 = 2x - 8 + 6
18 - 3x = 2x - 2
18 + 2 = 2x + 3x
20 = 5x
4 = x 

Answer 2

Aplicamos distributiva en: 3(3-x) = 9 - 3x ; y 2(x-4) = 2x-8
Luego:
9 - 3x + 9= 2x - 8 + 618 - 3x = 2x -218 + 2 = 2x + 3x20 = 5x4 = x