Question

Number 11. I'm not sure any help?

Answer 1

a). When Katherine was dividing the equation by 2, she handled the ' 2x '
correctly, and she handled the '16' correctly, but she forgot to divide the '7' by 2.

b). Here's what she should have done. I think this would be easier:

2x + 7 = 16

Subtract 7 from each side: 2x = 9

Divide each side by 2 : x = 4.5

Answer 2

2x+7=16
Katherine divided wrong. She shouldn't have divided by 2 because 7 isn't a multiple of 2; x+7≠16:2.

She should have proceed like that:
2x+7=16|-7
2x=16-7
2x=9
x=9:2
x=4,5