5x - (5x+3=-1/3 (12x+21)

Answer: x = - 1

Step-by-step explanation:

i assume you mean

5x - (5x+3) = - 1/3 (12x+21)

lets start with the left

- (5x+3) can be turnd into - 5x-3

now it is

5x-5x-3 and that can be just - 3

now lets go to the right and get rid of the 1/3

we see the 3 at the bottom of 1/3, and (12x+21) can be factored with 3

so 1/3 x 3 (4x+7) is what we get

1/3 x 3 cancels out so we are left with

-3 = (-4x-7)

lets try to get - 4x by itself

if you move - 4x to the left, turning it into 4x, and move - 3 to the right, turning it into 3, you get 4x = - 7 + 3

-7 + 3 = - 4

4x = - 4

devide by 4

4x/4 = - 4/4

x = - 1