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.

The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 52° - 31° = 97°

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.

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 equal sign and the answer on the other.

-4y - 5 = \( \frac{y}{5} \)
5 x (-4y - 5) = y
(5 x -4y) + (5 x -5) = y
-20y - 25 = y
-20y - 25 - y = 0
-20y - y = 25
-21y = 25
y = \( \frac{25}{-21} \)
y = -1\(\frac{4}{21}\)

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.