4n - 9 = -9 how do u solve?

#1-20 state whether the angles are alternate interior, alternate exterior, vertical, or corresponding angles.

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.

Mrs. sling bought a pound of green beans for $1.80. how much will mrs. tennison pay for 3 1/2 pounds of green beans?