Problem Solving

Which of the following equation has roots common with x2-6x+5=0?

a. x2+1 = 0
b. x2-x-2=0
c. x2-10x-5=0
d. 2x2-2=0
e. x2-2x-3=0

Answer is D. (sorry dont know how to hide the answer!)

This is simple problem, but i not able to understand the official answer. (x-5) (x-1) = 0, so factors are 5 and 1.

The official answers picked D has substituting 1 in the equation results in 0.

Why did we not substitute 5? If we do so then D doesn't make sense.

This problem is from Veritas prep material

Thanks everyone!

Hi

Probably the reason for choosing D was because it has at least 1 matching root. In the remaining options, there are no matches at all.

hmmm good point

thanks!!

sweet83 wrote:Which of the following equation has roots common with x2-6x+5=0?

a. x2+1 = 0
b. x2-x-2=0
c. x2-10x-5=0
d. 2x2-2=0
e. x2-2x-3=0

Answer is D. (sorry dont know how to hide the answer!)

This is simple problem, but i not able to understand the official answer. (x-5) (x-1) = 0, so factors are 5 and 1.

The official answers picked D has substituting 1 in the equation results in 0.

Why did we not substitute 5? If we do so then D doesn't make sense.

This problem is from Veritas prep material

Thanks everyone!

I think instead of asking "common roots" it should be "common root"

The Answer is D because only D has root in common with the given equation. 2(x^2 - 1) gives x = 1.. where initial equation has 5 and 1.
Note: The question did not ask for all the common roots, but only one common root.