Question

Determine the value of d that complete the square of x^2+dx+64​

Answer 1

d = 16

Explanation:

x² + dx + 64

since x² and 64 are perfect squares, this is of the form

(x + 8)²

= (x + 8)(x + 8) ← expand using FOIL

= x² + 8x + 8x + 64

= x² + 16x + 64 ← in the form x² + dx + 64

with d = 16