Express the number in terms of i

Need asap. solve for the following inequality

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! )

Which of the following vectors are orthogonal to (2,1)? check all that apply