Question

1.tính nhanh                                              a,(4+4)×(2019+2019+...+2019) "Có 125 số 2019"                 

b,(42+42+...+42)+(125+125+...+125)

 "Có 125 số 42 ;có 58 số 125"

Answer 1

a) (4+4)x(2019 +2019 +.....+2019)

= 8 x 125 x 2019

= (8 x 125) x 2019

= 1000 x 2019

= 2019000

b) ( 42+42+...+42)+(125+125+....+125)

= 42 x 125 + 58 x 125

= 125 x ( 42 + 58)

= 125 x 100

= 12500

Answer 2

 42+42+...+42)+(125+125+....+125)

= 42 x 125 + 58 x 125

= 125 x ( 42 + 58)

= 125 x 100

= 12500