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:

z² - 10z + 57 = 5z + 3
z² - 10z + 57 - 3 = 5z
z² - 10z - 5z + 54 = 0
z² - 15z + 54 = 0

Next, factor the quadratic equation:

z² - 15z + 54 = 0
(z - 6)(z - 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 6) or (z - 9) must equal zero:

If (z - 6) = 0, z must equal 6
If (z - 9) = 0, z must equal 9

So the solution is that z = 6 or 9

When solving an equation with two variables, 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.)

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.)

-9b(b - z)
-9(9)(9 + 4)
-9(9)(13)
(-81)(13)
-1053

A rectangle is a parallelogram containing four right angles. Opposite sides (a = c, b = d) are equal and the perimeter is the sum of the lengths of all sides (a + b + c + d) or, comonly, 2 x length x width. The area of a rectangle is length x width. A square is a rectangle with four equal length sides. The perimeter of a square is 4 x length of one side (4s) and the area is the length of one side squared (s²).

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.

2a + 3a = 5a