
Jess D. answered 04/01/15
Tutor
New to Wyzant
Middle School, High School, and College Math Tutor
I don't know the current unit you're working on, but I would treat it as a distributive problem.
Step 1: Rewrite as 7 x (10 + 3)
Step 2: Distribute. 7x10=70 and 7x3=21
Step 3: Add the two products. 70+21=91