Question

tính nhanh 

a) ( 1200 + 60 ) : 12

b) ( 2100 - 42 0 : 21

Answer 1

b) 98

a) 105

Answer 2

\(\left(1200+60\right):12=1200:12+60:12\)

\(=100+5=105\)

\(\left(2100-42\right):21=2100:21-42:21\)

\(=100-2=98\)

Answer 3

A) (1200+60):12

=1200:12+60

=100+60

=160

B) (2100-420):21

=2100:21-420

=100-420

=-320

K mk nhé

Answer 4

a) (1200 + 60) : 12

= 1260 : 12 

= 105

b) (2100 - 42) : 21

= 2058 : 21

= 98

Answer 5

a) (1200 + 60) : 12

 = 1200 : 12 + 60 : 12

 = 100 + 5 = 105

b) (2100 - 42) : 21

 = 2100 : 21 - 42 : 21

 = 100 - 2 = 98

Answer 6

làm

a) (1200+60 ) : 12

= 1200:12+60:12

=100         + 5

=105

b) ( 2100-420) : 21

= 2100:21-420:21

=100-20

=80