How to solve polynomial multiple choices?

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

1 Answer
Jim G.
Dec 22, 2017

#"see explanation"#

Explanation:

#(9)to(A)#

#(10)to(B)#

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

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

#x^2+a=0rArrx^2=-a#

#"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)#

Related questions
Impact of this question
1000 views around the world
You can reuse this answer
Creative Commons License