* 2. Mr. Clarke is looking for some new golf clubs. Academy Sports has a $300 set of
clubs on sale for $200. What percent has Mr. Clarke saved by purchasing the golf
clubs now?
A. $100.
B. 33%
C. 50%
D. 25%

Answer

Both are correct.

Explanation
The both equations are the same.
When we say that y=x+10, we can make x the subject of the formula and get;
y=x+10
y-10=x
x=y-10.

If the substitution is done correctly, that is x+10 for y and y-10 for x in the other equation then, both would be correct.