Theorem 2txmxeqx

Description: Two times a complex number minus the number itself results in the number itself. (Contributed by Alexander van der Vekens, 8-Jun-2018)

	Ref	Expression
Assertion	2txmxeqx	⊢ ( 𝑋 ∈ ℂ → ( ( 2 · 𝑋 ) − 𝑋 ) = 𝑋 )

Proof

Step	Hyp	Ref	Expression
1		id	⊢ ( 𝑋 ∈ ℂ → 𝑋 ∈ ℂ )
2		2times	⊢ ( 𝑋 ∈ ℂ → ( 2 · 𝑋 ) = ( 𝑋 + 𝑋 ) )
3	1 1 2	mvrladdd	⊢ ( 𝑋 ∈ ℂ → ( ( 2 · 𝑋 ) − 𝑋 ) = 𝑋 )