A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

b² + 4b - 5 = 0
(b - 1)(b + 5) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 1) or (b + 5) must equal zero:

If (b - 1) = 0, b must equal 1
If (b + 5) = 0, b must equal -5

So the solution is that b = 1 or -5

The slope-intercept equation for a line is y = mx + b where m is the slope and b is the y-intercept of the line. From the graph, you can see that the y-intercept (the y-value from the point where the line crosses the y-axis) is -2. The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, -7) and (2, 3) so the slope becomes:

Plugging these values into the slope-intercept equation:

y = 2\(\frac{1}{2}\)x - 2

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

4a³ - 5a³ = -1a³

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 + 9)(y - 2)
(y x y) + (y x -2) + (9 x y) + (9 x -2)
y² - 2y + 9y - 18
y² + 7y - 18