Question

Find the value of c that completes the square

x^2-16x+c

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

Answer 1

c = 64

Explanation:

Given

x² - 16x + c

To complete the square

add ( half the coefficient of the x- term )² to x² - 16x

x² + 2(- 8)x + 64

= (x - 8)²

Thus

x² - 16x + 64 = (x - 8)² ← a perfect square

with c = 64