Salt was mixed with pure water in a 1:3 proportion. What is the percentage of salt in the new solution?

For the right triangle shown, the lengths of two sides are given. find the third side. leave your answer in simplified, radical form.

David and alton are training for a race. they spend 35 minutes stretching and then go on a 5 mile practice run. david runs at a pace of 7 min/mile. alton runs at a pace of 8 min/mile. write an equation for each runner that shows the total length of their workout. then solve each equation showing your work

Find the value of x. also give me an explanation so i can complete it to other questions as well, : )