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 - 2)(y - 9)
(y x y) + (y x -9) + (-2 x y) + (-2 x -9)
y² - 9y - 2y + 18
y² - 11y + 18

A parallelogram is a quadrilateral with two sets of parallel sides. Opposite sides (a = c, b = d) and angles (red = red, blue = blue) are equal. The area of a parallelogram is base x height and the perimeter is the sum of the lengths of all sides (a + b + c + d).

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

-9b + x = -b - 2x + 3
-9b = -b - 2x + 3 - x
-9b + b = -2x + 3 - x
-8b = -3x + 3
b = \( \frac{-3x + 3}{-8} \)
b = \( \frac{-3x}{-8} \) + \( \frac{3}{-8} \)
b = \(\frac{3}{8}\)x - \(\frac{3}{8}\)

The perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 5cm + 8cm + 5cm = 18cm

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.

9y + 1 = \( \frac{y}{2} \)
2 x (9y + 1) = y
(2 x 9y) + (2 x 1) = y
18y + 2 = y
18y + 2 - y = 0
18y - y = -2
17y = -2
y = \( \frac{-2}{17} \)
y = -\(\frac{2}{17}\)