What is the area of the polygon?

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.