Emma solved this expression.

(15 - 13) x 6 = 1
2 x 7
14
What was her error? Explain.

Did you type in the entire question? Is there suppose to be a variable in there somewhere?

PEMDAS

15-13 = 2
2*6 = 12
This would leave 12 on the Left side of the equation, and 1 on the Right.
12 = 1 is not a true statement.