Answer:
c = [tex]\frac{25}{4}[/tex]
Step-by-step explanation:
To make a perfect square
add ( half the coefficient of the x- term )² to x² + 5x
x² + 5x + ([tex]\frac{5}{2}[/tex] )²
= x² + 5x + [tex]\frac{25}{4}[/tex]
= (x + [tex]\frac{5}{2}[/tex] )² ← a perfect square
