A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.

4z + 5 = \( \frac{z}{9} \)
9 x (4z + 5) = z
(9 x 4z) + (9 x 5) = z
36z + 45 = z
36z + 45 - z = 0
36z - z = -45
35z = -45
z = \( \frac{-45}{35} \)
z = -1\(\frac{2}{7}\)

The formula for area is πr²:

a = πr²
a = π(3²)
a = 9π

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.

-y + 2 < \( \frac{y}{9} \)
9 x (-y + 2) < y
(9 x -y) + (9 x 2) < y
-9y + 18 < y
-9y + 18 - y < 0
-9y - y < -18
-10y < -18
y < \( \frac{-18}{-10} \)
y < 1\(\frac{4}{5}\)

A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.