Question

bài 1:đơn giản phép tính

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

Answer 1

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

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

\(=2b\)

k mk nha 

thank you

Answer 2

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

=-d+d=0; a+(-a)=0; c+(-c)=0

=> =2.b

Answer 3

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

\(=a+b+c-d-a+b-c+d\)  ( phá ngoặc )

\(=a-a+b+b+c-c-d+d\) ( giao hoán )

\(=0+2b+0+0\)

\(=2b\)