=(5/30+3/30+2/30) : (5/30+3/30-2/30)

=10/30 : 5/30

=10/30 x 30/5

=2

!!! Hok tốt!!!

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}-\frac{1}{15}\right)\)

=\(\frac{10}{30}:\frac{6}{30}\)

\(=\frac{5}{3}\)

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}-\frac{1}{15}\right)\)

\(=\left(\frac{5}{30}+\frac{3}{30}+\frac{2}{30}\right):\left(\frac{5}{30}+\frac{3}{30}-\frac{2}{30}\right)\)

\(=\left(\frac{5+3+2}{30}\right):\left(\frac{5+3-2}{30}\right)\)

\(=\frac{8}{30}:\frac{6}{30}\)

\(=\frac{8}{30}\times\frac{30}{6}\)

\(=\frac{4}{1}\times\frac{1}{3}\)

\(=\frac{4}{3}\)

1 nha bạn

k mik nhé

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right)=1\)

(1/6 + 1/10 + 1/15) : (1/6 +1/10 +1/15)=1 

Chúc bạn học tốt!

a) Ta có:

\(\begin{array}{l}\frac{6}{{10}} = \frac{{6:2}}{{10:2}} = \frac{3}{5};\\\frac{9}{{15}} = \frac{{9:3}}{{15:3}} = \frac{3}{5}\end{array}\)

\(\begin{array}{l}\frac{{6 + 9}}{{10 + 15}} = \frac{{15}}{{25}} = \frac{{15:5}}{{25:5}} = \frac{3}{5};\\\frac{{6 - 9}}{{10 - 15}} = \frac{{ - 3}}{{ - 5}} = \frac{3}{5}\end{array}\)

Ta được: \(\frac{{6 + 9}}{{10 + 15}} = \frac{{6 - 9}}{{10 - 15}} = \frac{6}{{10}} = \frac{9}{{15}}\)

b) - Vì \(k = \frac{a}{b} \Rightarrow a = k.b\)

Vì \(k = \frac{c}{d} \Rightarrow c = k.d\)

- Ta có:

\(\begin{array}{l}\frac{{a + c}}{{b + d}} = \frac{{k.b + k.d}}{{b + d}} = \frac{{k.(b + d)}}{{b + d}} = k;\\\frac{{a - c}}{{b - d}} = \frac{{k.b - k.d}}{{b - d}} = \frac{{k.(b - d)}}{{b - d}} = k\end{array}\)

- Như vậy, \(\frac{{a + c}}{{b + d}}\) =\(\frac{{a - c}}{{b - d}}\) = \(\frac{a}{b}\) =\(\frac{c}{d}\)( = k)

a: \(\dfrac{6+9}{10+15}=\dfrac{15}{25}=\dfrac{3}{5};\dfrac{6-9}{10-15}=\dfrac{-3}{-5}=\dfrac{3}{5}\)

=>Bằng nhau

b: a/b=c/d=k

=>a=bk; c=dk

\(\dfrac{a+c}{b+d}=\dfrac{bk+dk}{b+d}=k;\dfrac{a-c}{b-d}=\dfrac{bk-dk}{b-d}=k\)

=>\(\dfrac{a+c}{b+d}=\dfrac{a-c}{b-d}=\dfrac{a}{b}=\dfrac{c}{d}\)

1/6 + 2/15 + 4/15 + 2/99 + 9/220 + 10/600

=( 1/6 + 1/60) + (2/15 + 4/15) + 2/99 + 9/220

=11/60 + 2/5 + 11/180

=7/12 + 11/180

=29/45

\(=\left(\frac{1}{6}+\frac{1}{60}\right)+\left(\frac{2}{15}+\frac{4}{15}\right)+\frac{2}{99}+\frac{9}{220}\)

\(=\frac{11}{60}+\frac{2}{5}+\frac{11}{180}=?\)

\(=\frac{7}{12}+\frac{11}{180}=?\)

\(=\frac{29}{45}.\)

1/6 + 2/15 + 4/15 + 2/99 + 9/220 + 10/600

= 1/6 + 2/15 + 4/15 + 2/99 + 9/220 + 1/60

= (1/6 + 1/60) + (2/15 + 4/15) + 2/99 + 9/220

= (10/60 + 1/60) + 2/5  + 2/99 + 9/220

= 11/60 + 2/5 + 2/99 + 9/220

= (11/60 + 2/5) + (2/99 + 9/220)

= (11/60 + 24/60) + 11/180

= 7/12 + 11/180

= 29/45

\(\left(\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right):\left(\frac{1}{6}+\frac{1}{10}-\frac{1}{15}\right)\)

=\(\frac{1}{3}+\frac{1}{5}\)

=\(\frac{5}{3}\)

5/3 nhé bạn k nha 

5/3 nha bạn tk mình nha

\(\frac{5.18-10.27+15.36}{10.36-20.54+30.72\left(not27\right)}=\frac{5.18-10.27+15.36}{4\left(5.18-10.27+15.36\right)}=\frac{1}{4}\)

\(\frac{\frac{-6}{7}+\frac{6}{19}-\frac{6}{31}}{\frac{9}{7}-\frac{9}{19}+\frac{9}{31}}=\frac{-6\left(\frac{1}{7}-\frac{1}{19}+\frac{1}{31}\right)}{9\left(\frac{1}{7}-\frac{1}{19}+\frac{1}{31}\right)}=\frac{-6}{9}=\frac{-2}{3}\)

sắp xếp theo thứ tự tăng dần là:

\(\Rightarrow-\frac{2}{15};-\frac{1}{10};\frac{1}{6};\frac{1}{5};\frac{4}{15};\frac{1}{3}\)

mình nghĩ là ta nên quy đồng trước