Subtracting 4mn from the sum of 2mn and 2mn gives
0
mn
2mn
−2mn
We shall first find the sum of 2mn and 2mn.
2mn+2mn=(2+2)mn=4mn
Now, we shall subtract 4mn from the above sum(which is 4mn).
i.e., 4mn−4mn=0
Question 60 (b)
What should be subtracted from −7mn+2m2+3n2 to get m2+2mn+n2?