Question

Tính nhanh :10 + 20 + 50 + 90 + 100 + 80 + 50

Answer 1

= 10 + 90 + 20 + 80 + 50 + 50 +100 = 100 + 100 + 100 + 100 = 400

Answer 2

\(10+20+50+90+100+80+50\)
\(=\left(10+90\right)+\left(20+80\right)+\left(50+50\right)+100\)
\(=100+100+100+100\)
\(=400\)

Answer 3

( 10+90) + (20+80)+ (50+50)+ 100

= 100+100+100+100

= 400

Answer 4

400

Answer 5

10 + 20 + 50 + 90 + 100 + 80 + 50

= ( 10 + 90 ) + ( 20 + 80 ) + ( 50 + 50 ) + 100

= 100 + 100 + 100 + 100

= 400

Answer 6

400

Answer 7

10 + 20 + 50 + 90 + 100 + 80 + 50 = 400 nha

Answer 8

= ( 50 + 50) + (80 + 20) + (90 + 10 ) + 100

= 100 + 100 + 100 + 100

= 400

Answer 9

Answer 10

   = ( 10 + 90 ) + ( 20 + 80 ) + ( 50 + 50 ) + 100

   =    10   +   90   +   20  + 80  +   50 +  50 + 100

   =              100   +     100 +   100 + 100

   =                                 400

Answer 11

10 + 20 + 50 + 90 + 100 + 80 + 50

= ( 10 + 90 ) + ( 20 + 80 ) + ( 50 + 50 ) + 100

= 100 + 100 + 100 + 100

= 400