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 -56 as well and sum (Inside, Outside) to equal 1. For this problem, those two numbers are -7 and 8. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² + y - 56
y² + (-7 + 8)y + (-7 x 8)
(y - 7)(y + 8)

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.

(8a)(9ab) + (9a²)(2b)
(8 x 9)(a x a x b) + (9 x 2)(a² x b)
(72)(a¹⁺¹ x b) + (18)(a²b)
72a²b + 18a²b
90a²b

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.

The surface area of a cylinder is 2πr² + 2πrh:

sa = 2πr² + 2πrh
sa = 2π(5²) + 2π(5 x 2)
sa = 2π(25) + 2π(10)
sa = (2 x 25)π + (2 x 10)π
sa = 50π + 20π
sa = 70π