To solve this equation, isolate the variable for which you are solving (c) on one side of the equation and put everything else on the other side.

7c + 8x = -8c + 2x - 8
7c = -8c + 2x - 8 - 8x
7c + 8c = 2x - 8 - 8x
15c = -6x - 8
c = \( \frac{-6x - 8}{15} \)
c = \( \frac{-6x}{15} \) + \( \frac{-8}{15} \)
c = -\(\frac{2}{5}\)x - \(\frac{8}{15}\)

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.

6a x 9b = (6 x 9) (a x b) = 54ab

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

sa = 2πr² + 2πrh
sa = 2π(4²) + 2π(4 x 2)
sa = 2π(16) + 2π(8)
sa = (2 x 16)π + (2 x 8)π
sa = 32π + 16π
sa = 48π

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 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.