The volume of a cylinder is πr²h:

v = πr²h
v = π(1² x 7)
v = 7π

You can only add or subtract monomials that have the same variable and the same exponent. For example, 2a + 4a = 6a and 4a² - a² = 3a² but 2a + 4b and 7a - 3b cannot be combined. However, you can multiply and divide monomials with unlike terms. For example, 2a x 6b = 12ab.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

y² - 5y + 6 = 0
(y - 2)(y - 3) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 2) or (y - 3) must equal zero:

If (y - 2) = 0, y must equal 2
If (y - 3) = 0, y must equal 3

So the solution is that y = 2 or 3

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.

(7a)(8ab) + (3a²)(9b)
(7 x 8)(a x a x b) + (3 x 9)(a² x b)
(56)(a¹⁺¹ x b) + (27)(a²b)
56a²b + 27a²b
83a²b

The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(4 + 9)(4)
a = ½(13)(4)
a = ½(52) = \( \frac{52}{2} \)
a = 26