Question

tính nhanh

a, 249 - ( 75 - 51 )

b, ( 4200 - 378 ) : 21

c, 2023 - ( 34 + 1560 ) 

d,  ( 1950 + 255 ) : 15 

e, 5.125.2.41.8

g, 4.36.25.50

h,25.7.10.4

i, 13.8.250

Answer 1

a) =249 - 24==225
b)3822:21=182
c) 2023-1594=429
d)2205:15=147
e) (125.8).(5.2.41)=1000.410=410000
g)4.25.36.50=180000
h) (25.4).(7.10)=100.70=7000
i)8.250.13=26000

Answer 2

a)249-(75-51)

=249-24

=225

b) (4200-378):21

=4200:21-378:21

=200-18

=182

Answer 3

e) 5.125.2.41.8

=(5.2).(125.8).41

=10.1000.41

=10000.41

=410000

Answer 4

h) 25.7.10.4

=(25.4).7.10

=100.7.10

=700.10

=7000

Answer 5

a)249-(75-51)

=249

b)(4200-378):21

=3822:21=182

c)2023-(34+1560)

=2023-1594=429

d)(1950+255):15

=2205:15=147

e)5.125.2.41.8

=(5.2).(125.8).41

=10.1000.41

=10000.41=410000