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

Madeline made a mistake in LINE 2

Step-by-step explanation:

We are given:

f(x) = 3x² + 6x − 7

Line 1: f(x) = 3(x² + 2x) − 7

Line 2: f(x) = 3(x² + 2x + 1 - 1) - 7

                 = 3(x²+2x+1)  -7 - 3

But Madeline wrote it 3(x² + 2x + 1) − 7 − 1

So, she made a mistake here

Line 3: f(x) = 3(x + 1)² − 10

So, Madeline made a mistake in LINE 2 and because of this LINE 3 was also wrong

he spend 5.1 minutes chatting with his friends

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5 1/10