A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r²h and the surface area is 2(π r²) + 2π rh.

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

z² + 5z - 14 = 0
(z - 2)(z + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 2) or (z + 7) must equal zero:

If (z - 2) = 0, z must equal 2
If (z + 7) = 0, z must equal -7

So the solution is that z = 2 or -7

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° - 28° - 66° = 86°

So, d° = 66° + 86° = 152°

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° - 28° = 152°

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.

-3y - 1 > -2 - 9y
-3y > -2 - 9y + 1
-3y + 9y > -2 + 1
6y > -1
y > \( \frac{-1}{6} \)
y > -\(\frac{1}{6}\)

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).