Please help. will mark brainliest

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3

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! )

What are the angle measures in triangle abc? m∠a = 90°,  m∠b = 30°,  m∠c = 60°m∠a = 60°,  m∠b = 90°,  m∠c = 30°m∠a = 90°,  m∠b = 60°,  m∠c = 30°m∠a = 60°,  m∠b = 30°,  m∠c = 90°