@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

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

anonymous · Answer

i think its B

solomonzelman · Answer

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

solomonzelman · Answer

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

anonymous · Answer

ok i get it now thank you