Simplify the left side.
5x−15+(4x+12)=3(x−1)
Simplify by adding terms.
Remove unnecessary parentheses.5x−15+4x+12=3(x−1)
Add 5x and 4x to get 9x.9x−15+12=3(x−1)
Add −15 and 12 to get −3.9x−3=3(x−1)
Simplify the right side.
Apply the distributive property.9x−3=3x+3⋅−1
Multiply 3 by −1 to get −3.9x−3=3x−3
Move all terms containing x to the left side of the equation.
Since 3x contains the variable to solve for, move it to the left side of the equation by subtracting 3x from both sides.9x−3−3x=−3
Subtract 3x from 9x to get 6x.6x−3=−3Move all terms not containing x to the right side of the equation.
Since −3 does not contain the variable to solve for, move it to the right side of the equation by adding 3 to both sides.6x=3−3Subtract 3 from 3 to get 0.6x=0Divide each term by 6 and simplify.x=0