To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y - 4)(y - 2)
(y x y) + (y x -2) + (-4 x y) + (-4 x -2)
y² - 2y - 4y + 8
y² - 6y + 8

When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.

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.

(6a)(4ab) - (7a²)(3b)
(6 x 4)(a x a x b) - (7 x 3)(a² x b)
(24)(a¹⁺¹ x b) - (21)(a²b)
24a²b - 21a²b
3a²b

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the < sign and the answer on the other.

-3c - 6 < \( \frac{c}{-6} \)
-6 x (-3c - 6) < c
(-6 x -3c) + (-6 x -6) < c
18c + 36 < c
18c + 36 - c < 0
18c - c < -36
17c < -36
c < \( \frac{-36}{17} \)
c < -2\(\frac{2}{17}\)