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

You can ride your bike around your block 6 times and the whole neighborhood 5 times in 16 minutes. you can ride your bike around your block 3 times and the whole neighborhood 10 times in 23 minutes. how long does it take you to ride around the neighborhood?