# How do you find the value of c that makes #x^2+5x+c# into a perfect square?

##### 1 Answer

Feb 20, 2017

#### Answer:

#### Explanation:

**Method 1**

Note that

So if

#(x+5/2)^2 = x^2+5x + (5/2)^2 = x^2+5x+25/4#

So

**Method 2**

#x^2+5x+c#

is in the form:

#ax^2+bx+c#

with

This has discriminant

#Delta = b^2-4ac = 25-4c#

So if