Group the first two terms and the last two terms.

Factor out the greatest common factor (GCF) from each group.

Factor the polynomial by factoring out the greatest common factor, .

Rewrite as .

Since both terms are perfect squares, factor using the difference of squares formula, where and .

Remove unnecessary parentheses.

If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .

Set the first factor equal to .

Add to both sides of the equation.

Set the next factor equal to .

Subtract from both sides of the equation.

Set the next factor equal to .

Add to both sides of the equation.

The final solution is all the values that make true.

Solve by Factoring x^3-5x^2-4x+20=0