Question

@undeadknight26 @phi @uri @Luigi0210

Find the values of k that make 2x2 + kx + 5 factorable.



A.
2 or 5


B.
7 or 11


C.
1 or 10


D.
1 or 5

Answer 1

i think its B

Answer 2

\(\normalsize\color{blue}{ \rm k^2-4(2)(5)=~ perfect~~square. }\)
\(\normalsize\color{blue}{ \rm k^2-40=~ perfect~~square. }\)
and \(\normalsize\color{blue}{ \rm k^2-40 }\) has to be more than zero

Answer 3

it can't be A C or D, because then the discriminant is imaginary.

Answer 4

ok i get it now thank you