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

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.

2a x 7b = (2 x 7) (a x b) = 14ab

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

a² + 10a + 16 = 0
(a + 2)(a + 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 2) or (a + 8) must equal zero:

If (a + 2) = 0, a must equal -2
If (a + 8) = 0, a must equal -8

So the solution is that a = -2 or -8

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.

9a⁹ - 7a⁹ = 2a⁹

The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c²) is equal to the sum of the two perpendicular sides squared (a² + b²): c² = a² + b² or, solved for c, \(c = \sqrt{a + b}\)