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 - 3)(y - 9)
(y x y) + (y x -9) + (-3 x y) + (-3 x -9)
y² - 9y - 3y + 27
y² - 12y + 27

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.

3a² - 6a² = -3a²

You need to find the value of b so solve the first equation in terms of y:

6b + y = -8
y = -8 - 6b

then substitute the result (-8 - 6b) into the second equation:

-8b - 4(-8 - 6b) = -9
-8b + (-4 x -8) + (-4 x -6b) = -9
-8b + 32 + 24b = -9
-8b + 24b = -9 - 32
16b = -41
b = \( \frac{-41}{16} \)
b = -2\(\frac{9}{16}\)

To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.

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

a = l x w
a = a x b
a = 2 x 6
a = 12