Answer:9a^2+18a-72
Step-by-step explanation:
9(a+1)^2-81
9(a+1)(a+1)-81
Open brackets
9(a^2+a+a+1)-81
9(a^2+2a+1)-81
9a^2+18a+9-81
9a^2+18a-72
12.5 (area of triangle) +40 (area of rectangle)=52.5
Answer:
b
Step-by-step explanation:
Answer:
Step-by-step explanation:
I don’t know