1/1991+ 1992*1990/1991 - 1992
without doing 4digit by 4digit multiplication
SHOW ME HOW the awnser -1
Do you seriously expect anyone to look at your questions when you ask in such a derogatory way?
Good question though.
Let x=199111991+1992×19901991−1992=1x+(x+1)(x−1)x−(x+1)=1x+x2−1x−(x+1)=x2+1−1x−(x+1)=x2x−(x+1)=x−x−1=−1
Substitution is always brilliant :)
You are just showing off Max LOL
LOL :P
+118703 
