Carolyn was asked to solve the following system of equations. Her work is shown. What error did Carolyn make? Identify her mistake and explain the error.

The mistake is on the second line of her work.

She wrote -2x + 4 when it should have been -2x -4 because she multiplied -2 by 2 the 4 would be negative: -2 x 2 = -4

Then adding 4 to the 7, x would be 11

the answer to this question is yes

twenty-six miles over two gallons because the proportion for the original 13 miles to one gallon would be written 13/1 and, doing the same thing to the top and bottom, i multiplied by 2 and got 26/2