To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -2 as well and sum (Inside, Outside) to equal -1. For this problem, those two numbers are -2 and 1. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - y - 2
y² + (-2 + 1)y + (-2 x 1)
(y - 2)(y + 1)

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

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 x 8b = (9 x 8) (a x b) = 72ab

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 3 x 3) + (2 x 3 x 9) + (2 x 3 x 9)
sa = (18) + (54) + (54)
sa = 126

To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.