Question

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solutions in english & spanish and tutorial videos at collegeprepalgebra.com
solving a quadratic equation by factoring
in exercises 17-26, solve the equation by factoring.

1. $x^{2}+2x=0$
2. $x^{2}-5x=0$
3. $-x^{2}+10x=0$
4. $-x^{2}-7x=0$
5. $x^{2}-25=0$
6. $x^{2}-121=0$
7. $x^{2}-3x-10=0$
8. $x^{2}+11x+24=0$
9. $x^{2}-10x+24=0$
10. $x^{2}-13x+42=0$

Explanation:

Step1: Factor out common term

$x^2 + 2x = x(x + 2) = 0$

Step2: Solve for x

Set each factor to 0: $x=0$ or $x+2=0$

Step1: Factor out common term

$x^2 - 5x = x(x - 5) = 0$

Step2: Solve for x

Set each factor to 0: $x=0$ or $x-5=0$

Step1: Factor out common term

$-x^2 + 10x = -x(x - 10) = 0$

Step2: Solve for x

Set each factor to 0: $-x=0$ or $x-10=0$

Step1: Factor out common term

$-x^2 - 7x = -x(x + 7) = 0$

Step2: Solve for x

Set each factor to 0: $-x=0$ or $x+7=0$

Answer:

$x=0$ or $x=-2$

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