Problem: If
N=5+15+2+5−2−3−22
then N equals
Answer Choices:
A. 1
B. 22−1
C. 25
D. 25
E. None of these
Solution:
A direct calculation shows that
(5+15+2+5−2)2=2
and
3−22=2−22+1=(2−1)2
Since a radical sign denotes the positive square root,
N=2−(2−1)=1.