Suppose the sum of two integers is negative. Must both be negative

Which radical expression is a rational number? a. √ 360 b. √ 644 c. √ 225 d. √ 122

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! )

Layla answer 21 of the 25 questions on his history test correctly.what decimal represents the fraction of problem he answer incorrectly.