Question

thực hiện phép tính [tính hợp lí nếu có thể]

17.85+17.15+300

72.121+27.121+121

32.39+52.21-12.39+21.48

Answer 1

a.=17*(85+15)+300

=17*100+300

=1700+300=2000

b.=121*(72+27+1)

=121*100=12100

c.chịu

Answer 2

17.85+17.15+300

⇔ 17 . ( 85 + 15 + 300 )

⇔ 17 .  400

⇔ 6800

72.121+27.121+121

⇔ 121 .( 72 + 27 + 1 )

⇔ 121 . 100

⇔ 12100

32.39+52.21-12.39+21.48

⇔ 39 . ( 32 - 12 ) + 21 . ( 52 + 48 )

⇔  39 . 20 + 21 . 100

⇔ 780 + 2100

⇔ 2880

Answer 3

17 . 85 + 17 . 15 + 300

= 17 . ( 85 + 15 ) + 300

= 17 . 100 + 300

= 1 700 + 300

= 1 400

72 . 121 + 27 . 121 + 121

= 121 . ( 72 + 27 + 1 )

= 121 . 100

= 12 100

32 . 39 + 52 . 21 - 12 . 39 + 21 . 48

= 39 . ( 32 - 12 ) + 21 . ( 52 + 48 )

= 39 . 20 + 21 . 100

= 780 + 2 100

= 9 900