Tính một cách hợp lí. a) A = 32,125 – (6,325 + 12,125) – (37 + 13,675); b) c) C = 2021,2345 . 2020,1234 + 2021,2345 . (–2020,1234)

a) A = 32,125 – (6,325 + 12,125) – (37 + 13,675)

A = 32,125 – 6,325 – 12,125 – 37 – 13,675

A = (32,125 – 12,125) – (6,325 + 13,675) – 37

A = 20 – 20 – 37

A = –37

Vậy A = –37.

b) B=4,75+−123+0,52−3.−38

B=194+−1323+122−−98

B=194+−18+1222+98

B=194+−18+14+98

B=194+14+−18+98

B=204+88

B=5+1

B=6

 

 

 

 

 

 

 

Vậy B = 6.

c) C = 2021,2345 . 2020,1234 + 2021,2345 . (–2020,1234)

C = 2021,2345 . [2020,1234 + (–2020,1234)]

C = 2021,2345 . 0

C = 0

Vậy C = 0.