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

Line 2

Step-by-step explanation:

Madeline was completing the square, and her work is shown below

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

In completing the square method we need x^2 alone

Take out 3 from first two terms

In completing the square method, we take middle term 2 , divide by 2 and then square it

2/2 =1

1^2 = 1

Now add and subtract 1

Take out -1 , multiply with 3

Madeline made a mistake in Line 2 . she forgot to multiply 3 with -1

answer: 12

step-by-step explanation: