Metamath Proof Explorer


Theorem jm2.21

Description: Lemma for jm2.20nn . Express X and Y values as a binomial. (Contributed by Stefan O'Rear, 26-Sep-2014)

Ref Expression
Assertion jm2.21 A2NJAXrm N J+A21AYrm N J=AXrmN+A21AYrmNJ

Proof

Step Hyp Ref Expression
1 rmbaserp A2A+A21+
2 1 rpcnne0d A2A+A21A+A210
3 expmulz A+A21A+A210NJA+A21 N J=A+A21NJ
4 2 3 sylan A2NJA+A21 N J=A+A21NJ
5 zmulcl NJ N J
6 rmxyval A2 N JAXrm N J+A21AYrm N J=A+A21 N J
7 5 6 sylan2 A2NJAXrm N J+A21AYrm N J=A+A21 N J
8 rmxyval A2NAXrmN+A21AYrmN=A+A21N
9 8 adantrr A2NJAXrmN+A21AYrmN=A+A21N
10 9 oveq1d A2NJAXrmN+A21AYrmNJ=A+A21NJ
11 4 7 10 3eqtr4d A2NJAXrm N J+A21AYrm N J=AXrmN+A21AYrmNJ
12 11 3impb A2NJAXrm N J+A21AYrm N J=AXrmN+A21AYrmNJ