Question

Tính:

A= a(b - c) + b(c - a) + c(a - b)

Giúp mình với ạ!!🙏🙏

 

Answer 1

A = a ( b - c ) + b ( c - a ) +  c ( a - b )

A = ab - ac + bc -ba + ca - cb

A = ( ab - ba ) + ( - ac + ac ) + ( bc - cb ) 

A = 0 + 0 + 0 

A = 0 

Answer 2

\(A=a\left(b-c\right)+b\left(c-a\right)+c\left(a-b\right)\)

\(A=ab-ac+bc-ba+ca-cb\)

\(A=\left(ab-ba\right)+\left(-ac+ca\right)+\left(bc-cb\right)\)

\(A=0+0+0=0\)

Answer 3

\(A=a\cdot\left(b-c\right)+b\cdot\left(c-a\right)+c\cdot\left(a-b\right)\)   

\(=ab-ac+bc-ba+ca-cb\)   

\(=0\)