1+2+3+4+5+6+7+8+9+10

=(1+9)+(2+8)+(3+7)+(4+6)+(5+10)

=10+10+10+10+15

=10x4+15

=40+15

=55

k mình nhé 

tổng bằng 55

1 + 2 - 3 + 4 - 5 + 6 - 7 + 8 - 9 + 10 = 7

\(1+2-3+4-5+6-7+8-9+10=7\)

2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5 + 10

                                                      = 10 + 10 + 10 + 5 +10 = 45

Tk mh nhé, mơn nhìu !!!
` HOK TỐT ~

ai trả lời nhanh kb nha

đáp án: c

;

\(9-8+5+4+10+80+100\)

k mk 3 cái nha YHTC _ Minamoto Shizuka !

\(\frac{2}{3}+\frac{9}{6}=\frac{4}{6}+\frac{9}{6}=\frac{4+9}{6}=\frac{13}{6}\)

\(\frac{4}{5}+\frac{25}{15}=\frac{12}{15}+\frac{25}{15}=\frac{12+25}{15}=\frac{37}{15}\)

\(\frac{20}{10}+\frac{8}{2}=2+4=6\)

\(\frac{2}{3}+\frac{9}{6}=\frac{2}{3}+\frac{3}{2}=\frac{4+9}{6}=\frac{15}{6}=\frac{5}{2}\)

\(\frac{4}{5}+\frac{25}{16}=\frac{64+125}{80}=\frac{189}{80}\)

45 ban nha

Đề sai nha bạn

Sửa đề

Tính:1+2+3+4+5+6+7+8+10

  = (1+9)+(2+8)+(3+7)+(4+6)+5+10

  =   10   +   10  +  10   +  10   +   15

 =       10 x 4 +15

=              55

1+2+3+4+5+6+7+8+9+10=55

11+100=111

1+52+35=88

1+2+3+4+5+6+7+8+9+10=55

11+100=111

1+52+35=88

\(1\frac{3}{5}x2\frac{4}{3}+\frac{2}{5}=\frac{8}{5}x\frac{10}{3}+\frac{2}{5}=\frac{16}{3}+\frac{2}{5}=\frac{86}{15}\)

1-1=0

1+3+4+5+4+8+2+9+4+6x0=0

1 - 1 = 0

1 + 3 + 4 + 5 + 4 + 8 + 2 + 9 + 4 + 6 x 0 = 0