Please help! Find the perimeter of the figure.

What number should be added to both sides of the equation to complete this square? x^2-10x=7

What is the solution of the systems of equations? y=2/3x+3 x=-2

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.