What is the solution to the system of equations y=-5x+30 x=10

Which of the following expressions is equal to 2x^2+8

At a sale this week, a desk is being sold for $213. this is a 29% discount from the original price. what is the original price?

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?