Question

  a)     – (45 + 91) – (- 17 + 45 – 91)

b) (- 57 – 84) – (31 – 57) – (- 84 + 31)

giúp mik với ah

Answer 1

a: =-45-91+17-45+91

=-90+17=-73

b: =-57-84-31+57+84-31

=-31-31=-62

Answer 2

a) \(-\left(45+91\right)-\left(-17+45-91\right)\)

\(=-45-91+17-45+91\)

\(=17+-\left(45+45\right)-\left(91-91\right)\)

\(=17-90-0\)

\(=-73\)

b) \(\left(-57-84\right)-\left(31-57\right)-\left(-84+31\right)\)

\(=-57-84-31+57+84-31\)

\(=\left(-57+57\right)-\left(84-84\right)+\left(-31+-31\right)\)

\(=0+0-62\)

\(=-62\)