WALLAHI HELP ME PLEASE WALLAHI HELP

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! )

Use matrices to solve this linear system: 5x1 − 2x2 = −30 2x1 − x2 = −13 x1 = x2 =

Idon’t know what to do after i plot my first shape