Megan wants to find the minimum value of the function y = x^2 - 10x + 3. She begins to convert the equation into vertex form by completing the square. Megan stops at the step below.

Question

y = (x + a)^2 + 3 + b

what number should Megan use to replace the a in this equation?

A. 25

B. -10

C. 100

D. -5​

Answer 1

well, x^2-10x+25 = (x-5)^2
so I'd pick a = -5
(and b = -25)

Answer 2

So it is -25?

Answer 3

NO. Read the question, and what I wrote.

Answer 4

oobleck said -5
the-25 is b

Answer 5

check
y = (x-5)^2 + 3 -25 = x^2 - 10x + 25+ 3 - 25
= x^2 - 10 x +3