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 + 7)(y + 7)
(y x y) + (y x 7) + (7 x y) + (7 x 7)
y² + 7y + 7y + 49
y² + 14y + 49

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 + 8x = 3b - 4x + 9
6b = 3b - 4x + 9 - 8x
6b - 3b = -4x + 9 - 8x
3b = -12x + 9
b = \( \frac{-12x + 9}{3} \)
b = \( \frac{-12x}{3} \) + \( \frac{9}{3} \)
b = -4x + 3

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.

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(5a)(7ab) - (3a²)(5b)
(5 x 7)(a x a x b) - (3 x 5)(a² x b)
(35)(a¹⁺¹ x b) - (15)(a²b)
35a²b - 15a²b
20a²b

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.

7a⁷ - 9a⁷ = -2a⁷