Find the slope of a line parallel to each given line. y=-1/5x-4

What is the value of x in the this question ?

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?

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! )