Question

Amigos una más :(
7x - [ (x+5) - (3x-1) ] = 12

Answer 1

7x - [ (x+5) - (3x-1) ] = 12

7x + -1[(x + 5) + -1(3x + -1)] = 12

7x + -1[(5 + x) + -1(3x + -1)] = 12

7x + -1[5 + x + -1(3x + -1)] = 12

7x + -1[5 + x + -1(-1 + 3x)] = 12
7x + -1[5 + x + (-1 * -1 + 3x * -1)] = 12
7x + -1[5 + x + (1 + -3x)] = 12

7x + -1[5 + 1 + x + -3x] = 12
7x + -1[6 + x + -3x] = 12
7x + -1[6 + -2x] = 12 7x + [6 * -1 + -2x * -1] = 12 7x + [-6 + 2x] = 12

-6 + 7x + 2x = 12 -6 + 9x = 12
-6 + 9x = 12
-6 + 6 + 9x = 12 + 6
0 + 9x = 12 + 6 9x = 12 + 6
9x = 18
x = 2