What strategies have you learned for solving proportions

What is the solution to the system of the equations? x = y - 3 x + 3y = 13

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.

Carlos by 24 mi and ran 6 miles what is the ratio of the distance carlos ran to the distance he biked