Question

1. Rút gọn biểu thức 
a) 2x+(-81)-(24-81)
b ) (-9-x+2)+9
c) 66-(12-x)+(12-66)
d) 15-(15-x+93)+93

Answer 1

a: =2x-81-24+81=2x-24

b: =-9+x+2+9=x+2

c: =66-12+x+12-66=x

d: =15-15+x-93+93=x

 

Answer 2

\(a=2x-81-24+81=2x-24\\ b=-9-x+2+9=-x+2\\ c=66-12+x+12-66=x\\ d=15-15+x-93+93=x\)

Answer 3

\(\text{a},2x-81-\left(-57\right)=2x-81+57=2x-24\\ b,=\left(-x-7\right)+9=-x-7+9=-x+2\\ c,=66-12+x+\left(-54\right)=54+x-54=x\\ d,=15-15+x-93+93=x\)