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

z² + 11z + 24 = 0
(z + 3)(z + 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 3) or (z + 8) must equal zero:

If (z + 3) = 0, z must equal -3
If (z + 8) = 0, z must equal -8

So the solution is that z = -3 or -8

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 - 5)(y - 1)
(y x y) + (y x -1) + (-5 x y) + (-5 x -1)
y² - y - 5y + 5
y² - 6y + 5

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.)

3c(c - x)
3(8)(8 - 4)
3(8)(4)
(24)(4)
96

The perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 14cm + 9cm + 7cm = 30cm

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.

8a + 7a = 15a