Đáp án:
Bài 2:
a/ 27 . 85 + 15 . 27= 27.(85+15)= 27.100= 2700
b/ 67 : 64 – 25 . 2 + 20200= 67/64-50+20200= 67/64+20150=1289667/64= 20151,04688
c/ 50.{272 : [12 – 4 + 2.(16 - 8)2]}= 50.{272 : [12 – 4 + 2.12.2]}= 50.{272 : [12 – 4 + 48]}= 50.{272 : 56}= 50.34/7= 1700/7
Bài 3:
a/ 60. (x - 16) = 360
x-16 = 360:60
x-16 = 6
x = 6+16
x = 22
b/ 514 – 4.(1 + x) = 390
- 4.(1+x) = 390-514
- 4.(1+x) = -124
(1+x) = -124:(-4)
1+x = 31
x = 31-1
x = 30