Bài tập Toán lớp 6: Phép trừ và phép chia

a, 125.98 – 125.46 – 52.25

= 125.(98 - 46) – 52.25

= 125.52 – 52.25

= 52.(125 - 25)

= 52.100

= 5200

b, 53.39 – 53.21 + 47.39 – 47.21

= 53.(39 - 21) + 47.(39 - 21)

= 53.18 + 47.18

= 18.(53 + 47)

= 18.100

= 1800

c, 27.121 – 87.27 + 73.34

= 27.(121 - 87) + 73.34

= 27.34 + 73.34

= 34.(27 + 73)

= 34.100

= 3400

d, 256256.397 – 397397.256

= 1001.256.397 – 397.1001.256 = 0

a, 234 + (345 - x) = 500

345 – x = 500 – 234

345 – x = 266

x = 345 – 266

x = 79

b, (5x - 15) : 7 = 40

5x – 15 = 40.7

5x – 15 = 280

5x = 280 + 15

5x = 295

x = 295 : 5

x = 59

c, 24x + 48 = 2016

24x = 2016 – 48

24x = 1968

x = 1968 : 24

x = 82