ANSWER IT ONLY IF YOU KNOW THE ANSWER. IF YOU DONT KNOW DONT ANSWER IT. Make sure you explain please! Which of the following shows the correct first step to solve x^2 - 16x = -21 by completing the square?

A)x^2 - 16x + 64 = -21

B) x^2 - 16x + 64 = -21 + 64

C) x^2 - 16x + 16 = -21 + 16

D) x^2 - 16x + 8 = -21 + 8

B)

Step-by-step explanation:

The first step to completing the square is by dividing "b" by 2, squaring that number, and adding it on both sides. In this case, 16/2 = 8 and 8 squared = 64. In answer choice B, this is correctly added to both sides of the equation.

See the full steps for completing the square below. If you're still stuck on this, I suggest watching the completing the square video on Tutors.com. It is very helpful!

Have a great day!

the answer is b.

step-by-step explanation:

identity property is where 0+whatever number=whatever number. basically 0+ a number.