Đặt b+c=x ta được:
A=(a+x)3+(a-x)3-6a.x2
=a3+3a2x+3ax2+x3+a3-3a2x+3ax2-x3-6ax2
=2a3
Đặt b+c=x ta được:
A=(a+x)3+(a-x)3-6a.x2
=a3+3a2x+3ax2+x3+a3-3a2x+3ax2-x3-6ax2
=2a3
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A=\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn:
A= ( a+b+c) \(^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
rút gọn
\(\left(a+b+c\right)^3-\left(b+c-a\right)^3-\left(a+c-b\right)^3-\left(a+b-c\right)^3\)