Question

tính nhanh ;

10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 + 100

tk nhé

Answer 1

\(10+20+30+40+50+60+70+80+90+100\)

\(=\left(10+90\right)+\left(20+80\right)+\left(30+70\right)+\left(40+60\right)+100+50\)

\(=100+100+100+100+100+50\)

\(=550\)

Answer 2

 = ( 10 + 90 ) + ( 20 + 80) + ( 30 + 70 ) + ( 40 + 60 ) + 50 + 100

=  100            +       100     +        100    +       100       +     50 + 100

= 100 x 5 + 50

= 500 + 50

= 550

tk nhé 

Answer 3

lop 3

10+90=100

20+80=100

30+70=100

40+60=100

100    =100

..50....=  50

100X5+50=550

Answer 4

550 bn nhe

chuc may man,nho tk mk nha