Question

Rút gọn biểu thức sau:

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

B=(a+b+c)-(a+b-5)

Answer 1

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

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

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

\(A=-c\)

\(B=(a+b+c)-(a+b-5)\)

\(B=a+b+c-a-b+5\)

\(B=(a-a)+(b-b)+c+5\)

\(B=c+5\)

Answer 2

\(\: \: \: ­\: ­\: ­\: •A=\left(a-b\right)-\left(a-b+c\right)=a-b-a+b-c\\ A=c\\ B=\left(a+b+c\right)-\left(a+b-5\right)\\ \: \: ­\: ­\: ­\: •B=a+b+c-a-b+5\\ B=c+5\)

Answer 3

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

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

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

\(A=0+0-c\)

\(A=-c\)

\(B=\left(a+b+c\right)-\left(a+b-5\right)\)

\(B=a+b+c-a-b+5\)

\(B=\left(a-a\right)+\left(b-b\right)+c+5\)

\(B=c+5\)

Answer 4

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

A = a-b-a+b-c

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

A = 0 + 0 - c

A = -c

B= ( a+b+c)-(a+b-5 )

B = a+b+c-a-b + 5

B = ( a - a ) + ( b - b ) + c + 5

B = 0 + 0 + c + 5

B = c + 5