\(\frac{1}{3}+\frac{1}{9}+\frac{1}{18}+\frac{1}{30}+..+\frac{1}{135}\)

\(=\frac{1}{3}+\frac{1}{9}+\frac{1}{18}+\frac{1}{30}+\frac{1}{45}+\frac{1}{63}+\frac{1}{84}+\frac{1}{108}+\frac{1}{135}\)

\(=\frac{1}{1\times3}+\frac{1}{3\times3}+\frac{1}{3\times6}+\frac{1}{6\times5}+\frac{1}{5\times9}+\frac{1}{9\times7}+\frac{1}{7\times12}+\frac{1}{12\times9}+\frac{1}{9\times15}\)

\(=1-\frac{1}{3}+\frac{1}{3}-\frac{1}{3}+\frac{1}{3}-\frac{1}{6}+\frac{1}{6}-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{7}+\frac{1}{7}-\frac{1}{12}+\frac{1}{12}-\frac{1}{9}+\frac{1}{9}-\frac{1}{15}\)

( gạch bỏ các phân số giống nhau )

\(=1-\frac{1}{15}\)

\(=\frac{14}{15}\)

CHÚC BẠN HỌC TỐT!!!!!

ta lấy mẫu số chung là 18

2/3 = 2x6/3x6 = 12/18

1/2 = 1x9/2x9 =9/18

ủng hộ mk nha

cái đề kiểu gì vậy hình như là sai đề rồi đó

a, \(\frac{2}{3}+\frac{2}{3}+\frac{6}{3}=\frac{10}{3}\)

b,\(\frac{3}{4}+\frac{3}{4}+\frac{3}{2}=\frac{6}{4}+\frac{3}{2}=\frac{3}{2}+\frac{3}{2}=\frac{6}{2}=3\)

Phép 1 : = 46579,75 nha

\(\frac{18}{20}\)=\(\frac{9}{10}\)vì mấy phép tính trên đổi sai hết đơn vị.

9/10 dau ghac cheo kia la sao

đúng thì h nha

\(\frac{7}{18};\frac{4}{18};\frac{6}{18}\)

Ta có: 272727x28 - 282828x27 = 27x10101x28 - 28x10101x27 = 0

Vậy, phép tính đã cho bằng 0

4) \(\frac{29x101-101}{2x19x101+4x101}\)

= \(\frac{\left(29-1\right)x101}{\left(38-4\right)x101}\)

=\(\frac{28}{34}=\frac{14}{17}\)

5) \(\left(\frac{2}{7}+\frac{11}{7}+\frac{1}{7}\right)-\frac{3}{8}-\frac{5}{8}+\frac{1}{3}\)

= \(\frac{14}{7}-\frac{8}{8}+\frac{1}{3}\)

= \(2-1+\frac{1}{3}=\frac{4}{3}\)

Nhớ tk cho mình nhé

1\(\frac{423133x846267+423134}{423133x846267+423134}=1\))

\(\frac{\left(423133+1\right)x846267-423133}{423133x846267+423134}\)

=\(\frac{423133x846267+846267-423133}{423133x846267+423134}\)

= \(\frac{423133x846267+423134}{423133x846267+423134}\)

= 1

Nhớ tk cho mình nhé (các câu sau  làm riêng cho đỡ dài

\(6=\frac{6}{1}=\frac{12}{2}=\frac{24}{4}=\frac{48}{8}=\frac{96}{16}\)

\(5:9=\frac{5}{9}=\frac{10}{18}=\frac{20}{36}=\frac{40}{72}=\frac{80}{144}\)

\(1=\frac{3}{3}=\frac{5}{5}=\frac{7}{7}=\frac{9}{9}=\frac{11}{11}\)

\(0=\frac{0}{7}=\frac{0}{10}=\frac{0}{13}=\frac{0}{16}=\frac{0}{19}\)

Chúc em hok tốt!!!

Thanks you Trần Thị Hợp

1/3 + 3/2

= 2/6 + 9/6

= 11/6

\(\frac{1}{15}+\frac{4}{15}+\frac{5}{18}+\frac{7}{18}\)

\(=\left(\frac{1}{15}+\frac{4}{15}\right)+\left(\frac{5}{18}+\frac{7}{18}\right)\)

\(=\frac{5}{15}+\frac{12}{18}\)

\(=\frac13+\frac23\)

\(=\frac33=1\)

\(\frac{12}{18}+\frac{1}{3}+\frac{1}{7}+\frac{2}{8}+\frac{27}{36}+\frac{42}{49}\)

\(=\frac{2}{3}+\frac{1}{3}+\frac{1}{7}+\frac{1}{4}+\frac{3}{4}+\frac{6}{7}\)

\(=\left(\frac{2}{3}+\frac{1}{3}\right)+\left(\frac{1}{7}+\frac{6}{7}\right)+\left(\frac{1}{4}+\frac{3}{4}\right)\)

\(=1+1+1\)

\(=3\)