Use the quadratic formula to find the solutions.

Substitute the values , , and into the quadratic formula and solve for .

Simplify the numerator.

Raise to the power of .

Multiply by .

Multiply by .

Subtract from .

Rewrite as .

Pull terms out from under the radical, assuming positive real numbers.

Multiply by .

Simplify .

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Factor out of .

Cancel the common factor.

Rewrite the expression.

The final answer is the combination of both solutions.

Double roots

Solve Using the Quadratic Formula 28x^2-28x+7=0