Question

Will award 20 points

Answer 1

Distribute the number outside the parenthesis and do the equations in the parenthesis. If there is no sign in between the parenthesis, assume to multiply. 

Answer 2

#2:     $\frac{1}{2}(15)(13+17) =225$

#3:     $\frac{1}{2}(10)(9.4+3.6)=65$

Hope this helps!