6+3(4x+3)=-3(+7x)

Solution for 6+3(4x+3)=-3(+7x) equation:

6+3(4x+3)=-3(+7x)

We simplify the equation to the form, which is simple to understand 
6+3(4x+3)=-3(+7x)

Reorder the terms in parentheses
6+(+12x+9)=-3*(+7x)

Remove unnecessary parentheses
+6+12x+9=-3+*(+7x+)

Reorder the terms in parentheses
6+12x+9=+(-21x)

Remove unnecessary parentheses
+6+12x+9=-21x

We move all terms containing x to the left and all other terms to the right. 
+12x+21x=-6-9

We simplify left and right side of the equation. 
+33x=-15

We divide both sides of the equation by 33 to get x. 
x=-0.454545454545