Mr Gupta asked two of his students to solve the expression 
and write the answer on blackboard. Aryan wrote the answer as 3 a-4b5 whereas Ayan wrote the answer as 
. Who wrote the correct answer?
A Aryan
B Ayan
C Both of them
D None of these
That looks like 3a^4-b^5, not 3a^-4*b^5