The area of a parallelogram is equal to its length x width:

a = l x w
a = a x b
a = 9 x 2
a = 18

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.

-6b - 5y = 6b + 6y + 3
-6b = 6b + 6y + 3 + 5y
-6b - 6b = 6y + 3 + 5y
-12b = 11y + 3
b = \( \frac{11y + 3}{-12} \)
b = \( \frac{11y}{-12} \) + \( \frac{3}{-12} \)
b = -\(\frac{11}{12}\)y - \(\frac{1}{4}\)

To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -40 as well and sum (Inside, Outside) to equal -3. For this problem, those two numbers are -8 and 5. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 3y - 40
y² + (-8 + 5)y + (-8 x 5)
(y - 8)(y + 5)

The formula for circumference is circle diameter x π:

c = πd
c = 14π

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.