An equation is two expressions separated by an equal sign. The key to solving equations is to repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.

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

z² - 14z + 45 = 0
(z - 5)(z - 9) = 0

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

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

So the solution is that z = 5 or 9

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

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 5² + 8²
c² = 25 + 64
c² = 89
c = \( \sqrt{89} \)

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.