( Quick Response) Which expressions are equivalent?

Write the expression as a single natural logarithm. 2 in a - 4 in y

Will mark name all segments skew to bc

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! )