Theorem 9t2e18

Description: 9 times 2 equals 18. (Contributed by Mario Carneiro, 19-Apr-2015)

	Ref	Expression
Assertion	9t2e18	$$⊢9\cdot 2=18$$

Proof

Step	Hyp	Ref	Expression
1		9cn	$$⊢9\in ℂ$$
2	1	times2i	$$⊢9\cdot 2=9+9$$
3		9p9e18	$$⊢9+9=18$$
4	2 3	eqtri	$$⊢9\cdot 2=18$$