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.

-9c + 1 = -5 + 4c
-9c = -5 + 4c - 1
-9c - 4c = -5 - 1
-13c = -6
c = \( \frac{-6}{-13} \)
c = \(\frac{6}{13}\)

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

sa = 2πr² + 2πrh
sa = 2π(9²) + 2π(9 x 2)
sa = 2π(81) + 2π(18)
sa = (2 x 81)π + (2 x 18)π
sa = 162π + 36π
sa = 198π

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.)

-2c(c - x)
-2(9)(9 + 4)
-2(9)(13)
(-18)(13)
-234

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)(2ab) + (3a²)(8b)
(6 x 2)(a x a x b) + (3 x 8)(a² x b)
(12)(a¹⁺¹ x b) + (24)(a²b)
12a²b + 24a²b
36a²b

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 > sign and the answer on the other.

-2b - 3 > \( \frac{b}{-4} \)
-4 x (-2b - 3) > b
(-4 x -2b) + (-4 x -3) > b
8b + 12 > b
8b + 12 - b > 0
8b - b > -12
7b > -12
b > \( \frac{-12}{7} \)
b > -1\(\frac{5}{7}\)