Question

tính nhanh:

a. 119 + 24 + 81

b. 16 . 6 .125

c. 25 . 104

d. 12 . 19 + 12

e. 43 . 27 + 93 . 43 + 57 . 61 + 59 . 57

Answer 1

a, 119 + 24 + 81

= ( 119 + 81 ) + 24

= 200 + 24

= 224

b, 16 . 6 . 125

= 16 . 125 . 6

= 2000 . 6

= 12000

c, 25 . 104

= 25 . 100 + 25 . 4

= 2500 + 100

= 2600

d, 12 . 19 + 12 

= 12 . 19 + 12 . 1

= 12 . ( 19 + 1 )

= 12 x 20 

= 240

e, 43 . 27 + 93 . 43 + 57 . 61 + 59 . 57

= 43 . ( 27 + 93 ) + ( 61 + 59 ) . 57

= 43 . 120 + 120 . 57

= 120 . 43 + 120 . 57

= 120 . ( 43 + 57 )

= 120 . 100

= 12000

Answer 2

a/ 199 + 24 + 81 

= (119+81) + 24

= 200 + 24

= 224

b/ 16 . 6 . 125

= ( 16 . 125) . 6

= 2000 . 6

= 12000

c/ 25 . 104

= 25 . ( 100 + 4 )

= 25 . 100 + 25 . 4

= 2500 + 100

= 2600

d/43 . 27 + 93 . 43 + 57 . 61 + 59 . 57

= 43 . ( 27 + 93) + 57 . ( 61+ 59)

= 43 . 130 + 57 . 130

= (43 + 57) . 130

= 100 . 130

= 1300