Question

Find the value of c that completes the square

x^2+7x+c

Please help me with how to do this, and show me. Thank you.

Answer 1

c =
`(49)/(4)`

Explanation:

Given

x² + 7x + c

To complete the square

add ( half the coefficient of the x- term )² to x² + 7x

x² + 2(
`(7)/(2)` )x +
`(49)/(4)` , thus

= (x +
`(7)/(2)` )² ← a perfect square

with c =
`(49)/(4)`