How do you factor these:

1.) 2x2 + 5x

2.) x 2 - 81

3.) 9x2 - 25

1.) 2x2 + 5x

2.) x 2 - 81

3.) 9x2 - 25

1.) 2x2+ 5x

= x(2x + 5) {factor x out}

2.) x2 - 81

= (x + 9)(x - 9) {it is a difference of two squares}

3.) 9x2- 25

= (3x + 5)(3x - 5) {it is a difference of two squares}

- Algebra House

= x(2x + 5) {factor x out}

2.) x2 - 81

= (x + 9)(x - 9) {it is a difference of two squares}

3.) 9x2- 25

= (3x + 5)(3x - 5) {it is a difference of two squares}

- Algebra House