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)(7ab) + (2a²)(5b)
(9 x 7)(a x a x b) + (2 x 5)(a² x b)
(63)(a¹⁺¹ x b) + (10)(a²b)
63a²b + 10a²b
73a²b

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 45 as well and sum (Inside, Outside) to equal 14. For this problem, those two numbers are 5 and 9. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² + 14y + 45
y² + (5 + 9)y + (5 x 9)
(y + 5)(y + 9)

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.

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

a = ½bh
a = ½ x 1 x 9 = \( \frac{9}{2} \) = 4\(\frac{1}{2}\)

The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.