How do you solve x^2 - 45 = 0 using the quadratic formula?

1 Answer
Jul 15, 2017

See a solution process below:

Explanation:

To solve this problem using the quadratic formula we can rewrite the equation as:

1x^2 + 0x - 45 = 0

The quadratic formula states:

For ax^2 + bx + c = 0, the values of x which are the solutions to the equation are given by:

x = (-b +- sqrt(b^2 - 4ac))/(2a)

Substituting 1 for a; 0 for b and -45 for c gives:

x = (-0 +- sqrt(0^2 - (4 * 1 * -45)))/(2 * 1)

x = +- sqrt(0 - (-180))/2

x = +- sqrt(180)/2

x = +- sqrt(36 * 5)/2

x = +- (sqrt(36) * sqrt(5))/2

x = +- (6sqrt(5))/2

x = +- 3sqrt(5)