Question

rút gọn cách tính: 

(a+b)+(a+b+c)+(c-a+b)-(b-c)+(a-b-c-a)+(c+a)

Answer 1

a + b + a + b +c + c - a - b - b + c + a - b - c -a + c + a

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

Answer 2

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

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

\(=2a-b+3c\)

k mk nha 

thank you very much