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.

(8a)(6ab) - (9a²)(5b)
(8 x 6)(a x a x b) - (9 x 5)(a² x b)
(48)(a¹⁺¹ x b) - (45)(a²b)
48a²b - 45a²b
3a²b

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 3 x 4 = \( \frac{12}{2} \) = 6

The formula for circumference is circle diameter x π:

c = πd
c = 8π

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.