Question 60 (b)
What should be subtracted from −7mn+2m2+3n2 to get m2+2mn+n2?
In order to get solution, we will subtract m2+2mn+n2 from −7mn+2m2+3n2.
Required expression is
−7mn+2m2+3n2−(m2+2mn+n2)=−7mn+2m2+3n2−m2−2mn−n2
On combining the like terms,
=−7mn−2mn+2m2−m2+3n2−n2=−9mn+m2+2n2
So, if we subtract m2+2n2−9mn from −7mn+2m2+3n2, then we get m2+2mn+n2.