Question

Will Give Medal!

Madeline was completing the square, and her work is shown below. Identify the line where she made her mistake.

f(x) = 3x2 + 6x − 7
Line 1: f(x) = 3(x2 + 2x) − 7
Line 2: f(x) = 3(x2 + 2x + 1) − 7 − 1
Line 3: f(x) = 3(x + 1)2 − 8

Line 1
Line 2
Line 3
She did not make any mistakes

Answer 1

what do you think?

Answer 2

I was thinking the second one...

Answer 3

I mean first

Answer 4

there is nothing wrong in the Line1, she is just factoring out 3 form first two terms
yes correct. do you know why?

Answer 5

you were right at first

Answer 6

She was supposed to add one on the outside of the parentheses not subtract...?

Answer 7

it is line 2 but why?

Answer 8

no

Answer 9

Yea im not sure then...

Answer 10

if you ask Is it the -1 at the end?
then yes, it has to be -3 instead

Answer 11

its not suppose to be -1

Answer 12

Oh -3 that right i forgot about the 3 at the beginning... thanks lol

Answer 13

np