To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(3a)(3ab) + (3a²)(5b)
(3 x 3)(a x a x b) + (3 x 5)(a² x b)
(9)(a¹⁺¹ x b) + (15)(a²b)
9a²b + 15a²b
24a²b

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 + 11z - 12 = 5z - 5
z² + 11z - 12 + 5 = 5z
z² + 11z - 5z - 7 = 0
z² + 6z - 7 = 0

Next, factor the quadratic equation:

z² + 6z - 7 = 0
(z - 1)(z + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 1) or (z + 7) must equal zero:

If (z - 1) = 0, z must equal 1
If (z + 7) = 0, z must equal -7

So the solution is that z = 1 or -7

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 formula for area is πr²:

a = πr²
a = π(5²)
a = 25π

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

2a x 5b = (2 x 5) (a x b) = 10ab