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

c² + 6c - 7 = 0
(c - 1)(c + 7) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c - 1) or (c + 7) must equal zero:

If (c - 1) = 0, c must equal 1
If (c + 7) = 0, c must equal -7

So the solution is that c = 1 or -7

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

The volume of a cylinder is πr²h:

v = πr²h
v = π(9² x 8)
v = 648π

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, \(c = \sqrt{a + b}\)

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.