A trapezoid is a quadrilateral with one set of parallel sides.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

c² - c - 30 = 0
(c + 5)(c - 6) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 5) or (c - 6) must equal zero:

If (c + 5) = 0, c must equal -5
If (c - 6) = 0, c must equal 6

So the solution is that c = -5 or 6

A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.

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.

(4a)(6ab) - (7a²)(2b)
(4 x 6)(a x a x b) - (7 x 2)(a² x b)
(24)(a¹⁺¹ x b) - (14)(a²b)
24a²b - 14a²b
10a²b

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

6a + 3a = 9a