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15) Solve. −x2 = 2x − 15 A) x = 3, x = 5 B) x = −3, x = 5 C) x = 3, x = −5 D) x = −3, x = −5

1 Answer

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Answer:

x=-5 x=3

Explanation:

−x2 = 2x − 15

Add x^2 to each side

x^2−x2 =x^2+ 2x − 15

0 = x^2+ 2x − 15

Factor

What two numbers multiply to -15 and add to 2

5*-3 = -15

5-3 =2

(x+5) (x-3) =0

Using the zero product property

x+5 =0 x-3=0

x+5-5=0-5 x-3+3=0+3

x=-5 x=3

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