For starters, follow through this problem on the order of operations. PEMDAS is the one I use, but I’ve seen others. It stands for Parenthesis Exponents Multiplication Division Addition Subtraction. You can’t do anything inside the parenthesis and there are no exponents, so we skip to the multiplication. That -2 outside of the parenthesis is what you multiply by. So, your equation then becomes 7x -6x +12. Combining like terms, you are left with x + 12. If what are looking for is substituting -3 in for x, that’s also easy. Just put -3 in place of all the x’s and again follow through order of operations. 7(-3)-2[4(-3)-6] is what you should start off looking like. Doing your multiplication, you have -21 -2(-12-6). Go to your parenthesis, -21 -2(-18). Multiply, -21 + 36. And finally, add. If using substitution, your answer is 15. I did both equations because I didn’t know which way they were supposed to be drone because that x= -3 thing was confusing me. I hope this helped though. :)