Metamath Proof Explorer


Theorem muldivdir

Description: Distribution of division over addition with a multiplication. (Contributed by AV, 1-Jul-2021)

Ref Expression
Assertion muldivdir
|- ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( ( C x. A ) + B ) / C ) = ( A + ( B / C ) ) )

Proof

Step Hyp Ref Expression
1 simp3l
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> C e. CC )
2 simp1
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> A e. CC )
3 1 2 mulcld
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( C x. A ) e. CC )
4 divdir
 |-  ( ( ( C x. A ) e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( ( C x. A ) + B ) / C ) = ( ( ( C x. A ) / C ) + ( B / C ) ) )
5 3 4 syld3an1
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( ( C x. A ) + B ) / C ) = ( ( ( C x. A ) / C ) + ( B / C ) ) )
6 3anass
 |-  ( ( A e. CC /\ C e. CC /\ C =/= 0 ) <-> ( A e. CC /\ ( C e. CC /\ C =/= 0 ) ) )
7 6 biimpri
 |-  ( ( A e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( A e. CC /\ C e. CC /\ C =/= 0 ) )
8 7 3adant2
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( A e. CC /\ C e. CC /\ C =/= 0 ) )
9 divcan3
 |-  ( ( A e. CC /\ C e. CC /\ C =/= 0 ) -> ( ( C x. A ) / C ) = A )
10 8 9 syl
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( C x. A ) / C ) = A )
11 10 oveq1d
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( ( C x. A ) / C ) + ( B / C ) ) = ( A + ( B / C ) ) )
12 5 11 eqtrd
 |-  ( ( A e. CC /\ B e. CC /\ ( C e. CC /\ C =/= 0 ) ) -> ( ( ( C x. A ) + B ) / C ) = ( A + ( B / C ) ) )