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 + 9y + 39 = -4y - 3
y² + 9y + 39 + 3 = -4y
y² + 9y + 4y + 42 = 0
y² + 13y + 42 = 0

Next, factor the quadratic equation:

y² + 13y + 42 = 0
(y + 6)(y + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 6) or (y + 7) must equal zero:

If (y + 6) = 0, y must equal -6
If (y + 7) = 0, y must equal -7

So the solution is that y = -6 or -7

To solve this equation, 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.)

4c(c - z)
4(2)(2 - 6)
4(2)(-4)
(8)(-4)
-32

An equation is two expressions separated by an equal sign. The key to solving equations is to 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.

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

a = ½bh
a = ½ x 7 x 9 = \( \frac{63}{2} \) = 31\(\frac{1}{2}\)

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.