# Maths teacher aroused our curiosity

When studying in school classes one day our Mathematics teacher wrote down a problem on the black board, which aroused our curiosity and also confused us. I recollect here the same;16 – 36 = 25 – 45 (both differences give the same value – 20)

Add a same constant 81/4 on both sides,

therefore 16 – 36 + 81/4 = 25 – 45 + 81/4

Carefully look at both sides, it is (4 – 9/2)² = (5 – 9/2)² .

Taking square root on both the sides gives 4 – 9/2 = 5 – 9/2.

Now just canceling the common term (-9/2) on both sides we have 4 = 5

How come this?