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

sa = 2πr² + 2πrh
sa = 2π(6²) + 2π(6 x 5)
sa = 2π(36) + 2π(30)
sa = (2 x 36)π + (2 x 30)π
sa = 72π + 60π
sa = 132π

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:

y² + 12y + 71 = -5y - 1
y² + 12y + 71 + 1 = -5y
y² + 12y + 5y + 72 = 0
y² + 17y + 72 = 0

Next, factor the quadratic equation:

y² + 17y + 72 = 0
(y + 8)(y + 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 8) or (y + 9) must equal zero:

If (y + 8) = 0, y must equal -8
If (y + 9) = 0, y must equal -9

So the solution is that y = -8 or -9

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 1 x 8 = \( \frac{8}{2} \) = 4

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.

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

7a - 8a = -1a