To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y - 9)(y - 4)
(y x y) + (y x -4) + (-9 x y) + (-9 x -4)
y² - 4y - 9y + 36
y² - 13y + 36

The formula for area is πr²:

a = πr²
a = π(5²)
a = 25π

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.

-4c + 9 > \( \frac{c}{-8} \)
-8 x (-4c + 9) > c
(-8 x -4c) + (-8 x 9) > c
32c - 72 > c
32c - 72 - c > 0
32c - c > 72
31c > 72
c > \( \frac{72}{31} \)
c > 2\(\frac{10}{31}\)

The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.