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.

5x - 1 < 1 - 8x
5x < 1 - 8x + 1
5x + 8x < 1 + 1
13x < 2
x < \( \frac{2}{13} \)
x < \(\frac{2}{13}\)

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

sa = 2πr² + 2πrh
sa = 2π(5²) + 2π(5 x 1)
sa = 2π(25) + 2π(5)
sa = (2 x 25)π + (2 x 5)π
sa = 50π + 10π
sa = 60π

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.

(8a)(9ab) + (9a²)(6b)
(8 x 9)(a x a x b) + (9 x 6)(a² x b)
(72)(a¹⁺¹ x b) + (54)(a²b)
72a²b + 54a²b
126a²b

A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.

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:

c² + 12c + 20 = 4c + 5
c² + 12c + 20 - 5 = 4c
c² + 12c - 4c + 15 = 0
c² + 8c + 15 = 0

Next, factor the quadratic equation:

c² + 8c + 15 = 0
(c + 3)(c + 5) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 3) or (c + 5) must equal zero:

If (c + 3) = 0, c must equal -3
If (c + 5) = 0, c must equal -5

So the solution is that c = -3 or -5