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

a = ½bh
a = ½ x 4 x 2 = \( \frac{8}{2} \) = 4

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

y² - y - 29 = -3y - 5
y² - y - 29 + 5 = -3y
y² - y + 3y - 24 = 0
y² + 2y - 24 = 0

Next, factor the quadratic equation:

y² + 2y - 24 = 0
(y - 4)(y + 6) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 4) or (y + 6) must equal zero:

If (y - 4) = 0, y must equal 4
If (y + 6) = 0, y must equal -6

So the solution is that y = 4 or -6

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.

-4a + 7 < -4 + 7a
-4a < -4 + 7a - 7
-4a - 7a < -4 - 7
-11a < -11
a < \( \frac{-11}{-11} \)
a < 1

An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 25° - 21° = 134°

So, d° = 21° + 134° = 155°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 25° = 155°

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.