Metamath Proof Explorer


Theorem muldivbinom2

Description: The square of a binomial with factor divided by a nonzero number. (Contributed by AV, 19-Jul-2021)

Ref Expression
Assertion muldivbinom2 A B C C 0 C A + B 2 C = C A 2 + 2 A B + B 2 C

Proof

Step Hyp Ref Expression
1 simpl A B A
2 simpr A B B
3 0cnd A B 0
4 1 2 3 3jca A B A B 0
5 mulsubdivbinom2 A B 0 C C 0 C A + B 2 0 C = C A 2 + 2 A B + B 2 0 C
6 4 5 stoic3 A B C C 0 C A + B 2 0 C = C A 2 + 2 A B + B 2 0 C
7 simp3l A B C C 0 C
8 simp1 A B C C 0 A
9 7 8 mulcld A B C C 0 C A
10 simp2 A B C C 0 B
11 9 10 addcld A B C C 0 C A + B
12 11 sqcld A B C C 0 C A + B 2
13 12 subid1d A B C C 0 C A + B 2 0 = C A + B 2
14 13 eqcomd A B C C 0 C A + B 2 = C A + B 2 0
15 14 oveq1d A B C C 0 C A + B 2 C = C A + B 2 0 C
16 sqcl B B 2
17 16 subid1d B B 2 0 = B 2
18 17 3ad2ant2 A B C C 0 B 2 0 = B 2
19 18 eqcomd A B C C 0 B 2 = B 2 0
20 19 oveq1d A B C C 0 B 2 C = B 2 0 C
21 20 oveq2d A B C C 0 C A 2 + 2 A B + B 2 C = C A 2 + 2 A B + B 2 0 C
22 6 15 21 3eqtr4d A B C C 0 C A + B 2 C = C A 2 + 2 A B + B 2 C