The expression of 1+21-2 is equivalent to which of the following :
A
1+232
B
-1-232
C
3+22
D
-3-22
Correct Answer: -1-232
1 + 21 - 2 = 1 + 21 + 21 - 21 + 2 = 1 + 221 - 2 = 1 + 22 + 22 - 1 = 1 + 22 + 2 - 1 = 3 + 22 - 1 = 3 - 1 + 22 - 1 = - 3 - 22