1. КВАДРАТ СУММЫ
a b
2
a 2ab b
2
2
a b
2
a 2ab b
2
b
a
a
a
2
2
a b
a b
b a b
b
a b
2
a b c
2
a b c 2ab 2ac 2bc
2
a
2
2
b
c
2
ab
ac
b ab
2
bc
bc
2
a
a
c ac
b
c
a b c d
2
a b c d 2ab 2ac 2ad
2bc 2bd 2cd
2
2
2
2
a
a a2
b
ab
c
ac
d
ad
b ab
2
bc
bd
bc
2
cd
cd
2
c ac
d ad
b
bd
c
d
mathematics
