a collector collect 77 coins- nickels, dimes, and quarters from parking meters downtown for a total of $6.40. there were 11 more dimes than quarters. How many of each type of coin did the collector collect?

Is the point (0, 8) on the x-axis or y-axis? how do you know?

The price of a visit to the dentist is calculated according to the formula 50+100n50+100n where nn is the number of cavities the dentist finds. on your last visit to the dentist, 22 cavities were found. what was the cost of your visit?

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! )