Question

Tinh nhanh: 15 + 25 + 85 + 75

Answer 1

15 + 25 + 85 + 75

= ( 15 + 85 ) + ( 25 + 75 )

= 100 + 100

= 200

Answer 2

( 15 + 85 ) +  ( 25 + 75 ) = 100 + 100

                                   =200

Answer 3

15+25+85+75

=(15+85)+(25+75)

=100+100

=100.2

=200

Answer 4

15 + 25 + 85 + 75

= ( 15 + 85 ) + ( 25 + 75 )

=       100      +     100

=    200

Answer 5

15 + 25 + 85 + 75

= ( 15 + 85 ) + ( 75 + 25 )

= 100     +      100

=         200.

Answer 6

= [ 15 + 85 ] + [ 25 + 75 ]

= 100 + 100 

= 200

Answer 7

15+25+85+75= (15+85)+(25+75)

                     = 100 + 100

                    = 200

Answer 8

15 + 25 + 85 + 75

= ( 15 + 85 ) + ( 25 + 75 )

= 100 + 100

= 200