How to solve polynomial multiple choices?

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Can someone please explain to me where I went wrong with question 9 and 10? I picked A and D. Thanks!

1 Answer
Dec 22, 2017

"see explanation"see explanation

Explanation:

(9)to(A)(9)(A)

(10)to(B)(10)(B)

(x^2+a)(x-b)(x+c)=0(x2+a)(xb)(x+c)=0

"equate each factor to zero and solve for x"equate each factor to zero and solve for x

x^2+a=0rArrx^2=-ax2+a=0x2=a

"this has no real solutions"this has no real solutions

x-b=0rArrx=b in RR^+

x+c=0rArrx=-c !inRR^+

rArr"equation has only 1 valid solution "to(B)