Question

Tính nhanh : 

12+13+14+15+15+16+17+18 =

1+2+3+4+5+6+7+8+9 =

 

Answer 1

105

45 k nha

Answer 2

12+ 13+ 14+ 15+ 16 +17 + 18=105

1+2+3+4+5+6+7+8+9=45

Answer 3

12 + 13 + 14 + 15 + 15 + 16 + 17 + 18

= ( 12 + 18 ) + ( 13 + 17 ) + ( 14 + 16 ) + ( 15 + 15 )

= 30 + 30 + 30 + 30

= 30 x 4

= 120

1 + 2 +3 + 4 + 5 + 6 + 7 + 8 + 9

= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5

= 10 + 10 + 10 + 10 + 5

= 10 x 4 + 5

= 40 + 5

 = 45

Answer 4

a14b5

Answer 5

12+13+14+15+16+17+18

=(12+18)+(13+17)+(14+16)

=30+30+30

=90

-

1+2+3+4+5+6+7+8+9

=(1+9)+(2+8)+(3+7)+(4+6)+5

=10+10+10+10+5

=45

Answer 6

120

45

Answer 7

12 + 13 + 14 + 15 + 15 + 16 + 17 + 18 = ?

=> 12 + 13 + 14 + 15 + 15 + 16 + 17 + 18 =  120

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = ?

=> 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = 45

Hok tốt nha (:

Answer 8

12+13+14+15+15+16+17+18

=(12+18)+(13+17)+(14+16)+(15+15)

=30+30+30+30

=120

1+2+3+4+5+6+7+8+9=

=(1+9)+(2+8)+(3+7)+(4+6)+5

=10+10+10+10+5

=45

hok tot

Answer 9

105 

45