To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y + 1)(y + 1)
(y x y) + (y x 1) + (1 x y) + (1 x 1)
y² + y + y + 1
y² + 2y + 1

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.

2b - 9 = \( \frac{b}{-4} \)
-4 x (2b - 9) = b
(-4 x 2b) + (-4 x -9) = b
-8b + 36 = b
-8b + 36 - b = 0
-8b - b = -36
-9b = -36
b = \( \frac{-36}{-9} \)
b = 4

A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.

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

sa = 2πr² + 2πrh
sa = 2π(7²) + 2π(7 x 3)
sa = 2π(49) + 2π(21)
sa = (2 x 49)π + (2 x 21)π
sa = 98π + 42π
sa = 140π

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 2 + 2 + 7 + 6
p = 17