The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

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.

(7a)(8ab) + (3a²)(3b)
(7 x 8)(a x a x b) + (3 x 3)(a² x b)
(56)(a¹⁺¹ x b) + (9)(a²b)
56a²b + 9a²b
65a²b

The surface area of a cylinder is 2πr² + 2πrh:

sa = 2πr² + 2πrh
sa = 2π(6²) + 2π(6 x 9)
sa = 2π(36) + 2π(54)
sa = (2 x 36)π + (2 x 54)π
sa = 72π + 108π
sa = 180π

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 equal sign and the answer on the other.

-3y + 5 = -6 + 5y
-3y = -6 + 5y - 5
-3y - 5y = -6 - 5
-8y = -11
y = \( \frac{-11}{-8} \)
y = 1\(\frac{3}{8}\)

A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.