Answer: Helen should have added 17 to both sides of the equation.
Explanation:
Hi, to answer this question we have to analyze Helen's Work:
X-17 =56
X-17+17 =56-17
X =39
In the second step she made a mistake, she added 17 to the left side of the equation and subtracted 17 to the right side of the equations.
Helen should have added 17 to both sides of the equation.
The correct way is:
X-17 =56
X-17+17 =56+17
X =73