All you do is insert -2 for a and 5 for b. So it becomes: 3(-2-4[5]). First you solve inside the parentheses because of pemdas (parentheses, exponents, multiplication/division, and addition/subtraction). The next step is multiplication, so you multiply -4 by 5 and end up with -20. So the problem is now 3(-2-20). Next you subtract -2 by 20 and get -22. Finally all you have left is 3(-22) Multiply that and get -66.
I'm sorry none of the answers worked but I triple checked my work. Many there's a typo?
