+0  
 
0
48
1
avatar+604 

For what real values of $a$ is $x^2 + ax + 25$ the square of a binomial? If you find more than one, then list your values in increasing order, separated by commas.

gueesstt  Apr 22, 2018
Sort: 

1+0 Answers

 #1
avatar+86613 
+1

x^2  + ax  +  25

 

Just like an earlier problem, set the discriminant to 0 and solve for a

 

So we have

 

a^2   -  4(1)(25)  = 0

 

a^2  - 100  = 0     factor this

 

(a - 10) (a + 10)  = 0

 

Setting both factors to 0 and solving for a  gives a  = 10   or a  = -10

 

So

 

a  = -10, 10

 

 

cool cool cool

CPhill  Apr 22, 2018

25 Online Users

avatar
avatar
New Privacy Policy (May 2018)
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  Privacy Policy