Question

Tính

1. (-34)+24+(-7)+27

2. 99+(-100)+101

3. (-75)+69+(-25)+131

Answer 1

1. (-34)+24+(-7)+27=-10+20=10

2.99+(-100)+101=(99+101)+(-100)=200-100=100

3.(-75)+69+(-25)+131=(69+131)-(75+25)=200-100=100

Answer 2

1) \(\left(-34\right)+24+\left(-7\right)+27\)

\(=-34+24-7+27\)

\(=-\left(34-24\right)-7+27\)

\(=-10-7+27\)

\(=-\left(10+7\right)+27\)

\(=-17+27\)

\(=27-17\)

\(=10\)

2) \(99+\left(-100\right)+101\)

\(=99-100+101\)

\(=-100+99+101\)

\(=-\left(100-99\right)+101\)

\(=-1+101\)

\(=101-1\)

\(=100\)

3) \(\left(-75\right)+69+\left(-25\right)+131\)

\(=-75+69-25+131\)

\(=-\left(75-69\right)-25+131\)

\(=-6-25+131\)

\(=-\left(6+25\right)+131\)

\(=-31+131\)

\(=131-31\)

\(=100\)

Answer 3

1. (-34) + 24 + (-7) + 27

= (-10) + 20

=10

2. 99 + (-100) +101

= (-1) + 101

=100

3. (-75) + 69 + (-25) + 131

= (-6) + (-25) +131

= (-31) + 131

= 100

=