Ten plus 6 times a number n is equal to 5 less than the number n

Brent wants to know what is 5 x 1/2

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

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! )