Now 4 = 3

Oh no!  Another crack in the foundations of mathematics!

Ahem.

Assume

a + b = c

This can be re-written as

4a – 3a + 4b – 3b = 4c – 3c

Rearrange some terms

4a + 4b – 4c = 3a + 3b – 3c

Factor out the coefficients

4 (a + b – c) = 3 (a + b – c)

Cancel out common terms on both sides

and you get

4 = 3

Blaaaaaaaaaaaaaargggggggggggghnnnn!!!