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.

For parallel lines with a transversal, the following relationships apply:

• angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
• alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
• all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other
• same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°)

Applying these relationships starting with w° = 15, the value of y° is 165.

Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).

The volume of a cylinder is πr²h:

v = πr²h
v = π(5² x 1)
v = 25π

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

b² - 14b + 45 = 0
(b - 5)(b - 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (b - 5) or (b - 9) must equal zero:

If (b - 5) = 0, b must equal 5
If (b - 9) = 0, b must equal 9

So the solution is that b = 5 or 9