To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(9a)(5ab) - (7a²)(7b)
(9 x 5)(a x a x b) - (7 x 7)(a² x b)
(45)(a¹⁺¹ x b) - (49)(a²b)
45a²b - 49a²b
-4a²b

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.

-2b + 5 = -5 - 6b
-2b = -5 - 6b - 5
-2b + 6b = -5 - 5
4b = -10
b = \( \frac{-10}{4} \)
b = -2\(\frac{1}{2}\)

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.

When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)