Problem:
If x>y>0, then yyxxxyyx​=
Answer Choices:
A. (x−y)y/x
B. (yx​)x−y
C. 1
D. (yx​)y−x
E. (x−y)x/y
Solution:
yyxxxyyx​=yy−xxy−x​=(yx​)y−x. One may verify that none of the other choices is correct by substituting x=2 and y=1.