Is 3 ! + 4 ! = 7 ! ?

Question

Philoid · Accepted Answer

Computing left hand side:

3!+4! = (3 × 2 × 1) + (4 × 3 × 2 × 1) = 6+24 = 30

Computing the right-hand side:

7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 = 5040

We observe that the left-hand side is not equal to the right-hand side.