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)(5ab) - (6a²)(8b)
(2 x 5)(a x a x b) - (6 x 8)(a² x b)
(10)(a¹⁺¹ x b) - (48)(a²b)
10a²b - 48a²b
-38a²b

An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 24° - 21° = 135°

So, d° = 21° + 135° = 156°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 24° = 156°

The volume of a cylinder is πr²h:

v = πr²h
v = π(2² x 7)
v = 28π

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

a = l x w
a = a x b
a = 4 x 9
a = 36

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.

4a x 5b = (4 x 5) (a x b) = 20ab