Metamath Proof Explorer


Theorem div32

Description: A commutative/associative law for division. (Contributed by Mario Carneiro, 27-May-2016)

Ref Expression
Assertion div32 ( ( 𝐴 ∈ ℂ ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ∧ 𝐶 ∈ ℂ ) → ( ( 𝐴 / 𝐵 ) · 𝐶 ) = ( 𝐴 · ( 𝐶 / 𝐵 ) ) )

Proof

Step Hyp Ref Expression
1 div23 ( ( 𝐴 ∈ ℂ ∧ 𝐶 ∈ ℂ ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ) → ( ( 𝐴 · 𝐶 ) / 𝐵 ) = ( ( 𝐴 / 𝐵 ) · 𝐶 ) )
2 divass ( ( 𝐴 ∈ ℂ ∧ 𝐶 ∈ ℂ ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ) → ( ( 𝐴 · 𝐶 ) / 𝐵 ) = ( 𝐴 · ( 𝐶 / 𝐵 ) ) )
3 1 2 eqtr3d ( ( 𝐴 ∈ ℂ ∧ 𝐶 ∈ ℂ ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ) → ( ( 𝐴 / 𝐵 ) · 𝐶 ) = ( 𝐴 · ( 𝐶 / 𝐵 ) ) )
4 3 3com23 ( ( 𝐴 ∈ ℂ ∧ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ) ∧ 𝐶 ∈ ℂ ) → ( ( 𝐴 / 𝐵 ) · 𝐶 ) = ( 𝐴 · ( 𝐶 / 𝐵 ) ) )