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.

9a - 7a = 2a

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.

(8a)(9ab) + (6a²)(3b)
(8 x 9)(a x a x b) + (6 x 3)(a² x b)
(72)(a¹⁺¹ x b) + (18)(a²b)
72a²b + 18a²b
90a²b

An acute angle measures less than 90°, a right angle measures 90°, and an obtuse angle measures more than 90°.

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.

(2a)(9ab) - (9a²)(7b)
(2 x 9)(a x a x b) - (9 x 7)(a² x b)
(18)(a¹⁺¹ x b) - (63)(a²b)
18a²b - 63a²b
-45a²b

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

-3c + 7y = -2c - 9y - 7
-3c = -2c - 9y - 7 - 7y
-3c + 2c = -9y - 7 - 7y
-c = -16y - 7
c = \( \frac{-16y - 7}{-1} \)
c = \( \frac{-16y}{-1} \) + \( \frac{-7}{-1} \)
c = 16y + 7