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.

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c²) is equal to the sum of the two perpendicular sides squared (a² + b²): c² = a² + b² or, solved for c, \(c = \sqrt{a + b}\)

To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

-7a + z = 2a - 6z + 2
-7a = 2a - 6z + 2 - z
-7a - 2a = -6z + 2 - z
-9a = -7z + 2
a = \( \frac{-7z + 2}{-9} \)
a = \( \frac{-7z}{-9} \) + \( \frac{2}{-9} \)
a = \(\frac{7}{9}\)z - \(\frac{2}{9}\)

To factor a quadratic expression, apply the FOIL (First, Outside, Inside, Last) method in reverse.