C(9 – 2) • 3=21 whats the answer

What is the total surface area of this square pyramid?

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )

Mia’s gross pay is 2953 her deductions total 724.15 what percent if her gross pay is take-home pay