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3 years ago

Which value of b would make x²+bx-30 factorable? A. -31 B. -17 C. 11 D. 13

Mathematics

2 answers:

oksian1 [2.3K]3 years ago

7 0

I think the answer is. D 14

dimulka [17.4K]3 years ago

5 0

Answer:

D. 13

Step-by-step explanation:

well since it's a quadratic equation, it can be written in the form of ax²+bx+c=0. So we have a=1, b=b and c= -30. Also the roots are given by the equation-

x= -b± $\sqrt{b^{2}-4ac}$ /2a. So all I did was put the number from the choices which would satisfy the sqrt part and that turned out to be 13 since $\sqrt{13^{2}-4*1*(-30)$ = $\sqrt{289}$ = 17. So b=13.

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2 years ago

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