Answer
69
Work Step by Step
We first follow the instructions to plug in -1 for a and -5 for b. According to order of operations, we first consider everything inside of the parenthesis. Because multiplication is before subtraction and addition in order of operations, once within the parenthesis, we first multiply, and then we add and subtract.
$3(2(-1)-5(-5))=3(-2+25))=3(23)=69$
