\(A=\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
\(=\left[a+\left(b+c\right)\right]^3+\left[a-\left(b+c\right)\right]^3-6a\left(b+c\right)^2\)
\(=a^3+3a^2\left(b+c\right)+3a\left(b+c\right)^2+\left(b+c\right)^3+a^3-3a^2\left(b+c\right)+3a\left(b+c\right)^2-\left(b+c\right)^3-6a\left(b+c\right)^2\)
\(=2a^3\)
Rút gọn biểu thức\(\left(a+b\right)^3+\left(b+c\right)^3+\left(c+a\right)^3-3\left(a+b\right)\left(b+c\right)\left(a+c\right)\)
Rút gon biểu thức sau:
\(\left(a+b+c\right)^3+\left(a-b-c\right)^3-6a\left(b+c\right)^2\)
Rút gọn biểu thức sau: \(\left(a+b\right)^3+\left(b+c\right)^3+\left(c+a\right)^3-3\left(a+b\right)\left(b+c\right)+\left(c+a\right)\)
Rút gọn: \(\left(a+b+c\right)^3-\left(b+c-a\right)^3-6a\left(b+c\right)^2\)
Rút gọn biểu thức sau: \(\left(a+b\right)^3+\left(b+c\right)^3+\left(c+a\right)^3-3\left(a+b\right)\left(b+c\right)\left(c+a\right)\)
Rút gọn biểu thức \(A=\left(a+b\right)^3-\left(a-b\right)^3-6a^2\)với a=-2
Rút gọn phân thức:
\(A=\frac{\left(b-c\right)^3+\left(c-a\right)^3+\left(a-b\right)^3}{a^2\left(b-c\right)+b^2\left(c-a\right)+c^2\left(a-b\right)}\)
Rút gọn phân thức :
\(\frac{a^3\left(b^2-c^2\right)+b^3\left(c^2-a^2\right)+c^3\left(a^2-b^2\right)}{a^2\left(b-c\right)-b^2\left(c-a\right)+c^2\left(a-b\right)}\)
Rút gọn biểu thức :
\(\dfrac{1}{a\left(a-b\right)\left(a-c\right)}+\dfrac{1}{b\left(b-a\right)\left(b-c\right)}\)
