Question

Rút gọn các biểu thức sau:

A=(71+x)+(-24-x)+(35-x)

B=x-31-[(15+x)-(23-x)]

C=(-15+x)+[25-(-x)]

Answer 1

\(A=\left(71+x\right)+\left(-24-x\right)+\left(35-x\right).\\A =71+x-24-x+35-x.\\ =82-x.\\ B=x-31-\left[\left(15+x\right)-\left(23-x\right)\right].\\ B=x-31-15-x+23-x.\\ B=-x-23.\\ C=\left(-15+x\right)+\left[25-\left(-x\right)\right].\\ C=-15+x+25+x.\\ C=10+2x.\)

Answer 2

\(A=\left(71+x\right)+\left(-24+x\right)+\left(35-x\right)\)

\(A=71+x-24-x+35-x\)

\(A=82-x\)

\(B=x-31-\left[\left(15+x\right)-\left(23-x\right)\right]\)

\(B=x-31-\left(15+x-23+x\right)\)

\(B=x-31-15-x+23-x\)

\(B=-23-x\)

\(C=\left(-15+x\right)+\left[25-\left(-x\right)\right]\)

\(C=-15+x+25+x\)

\(C=10+2x\)