what??

Bài Toán hay đấy

\(\frac{2}{3}\)-\(\frac{a}{b}\)+\(\frac{1}{4}\)=\(\frac{1}{6}\)

\(\frac{2}{3}\)-\(\frac{a}{b}\)            =\(\frac{1}{6}\)-\(\frac{1}{4}\)

\(\frac{2}{3}\)-\(\frac{a}{b}\)            =\(-\frac{1}{12}\)

                       \(\frac{a}{b}\)=\(\frac{2}{3}\)-\(-\frac{1}{12}\)

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

Vay \(\frac{a}{b}\)=\(\frac{3}{4}\)

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

\(\frac{a}{b}=\frac{1}{6}-\frac{1}{4}-\frac{2}{3}=\frac{-3}{4}\)

k mk nha

\(\frac{2}{3}-\frac{a}{b}+\frac{1}{4}=\frac{1}{6}\Rightarrow\frac{a}{b}=\frac{2}{3}-\frac{1}{6}+\frac{1}{4}\Rightarrow\frac{a}{b}=\frac{3}{4}\)

Theo đề bài ra, ta có :

\(\frac{a+14}{a+18}=\frac{a}{b}\)

\(\Rightarrow b\left(a+14\right)=a\left(b+18\right)\)

\(\Rightarrow ab+14b=ab+18a\)

\(\Rightarrow14b=18a\left(vì:ab=ab\right)\)

\(\Rightarrow\frac{a}{b}=\frac{14}{18}=\frac{7}{9}\)

Vậy số cần tìm là \(\frac{7}{9}\)

Theo bài ra ta có:

\(\frac{a+b}{b+b}=2.\frac{a}{b}\Rightarrow\frac{a+b}{2b}=\frac{2a}{b}\)

=>a/2b+b/2b=2a/b

=>a/2b+1/2=2a/b

=>2a/b-a/2b=1/2

=>4a/2b-a/2b=1/2

\(=>\frac{4a-a}{2b}=\frac{1}{2}\)

=>3a/2b=1/2

=>3/2.a/b=1/2

=>a/b=1/2:3/2=1/3

 Vì a/b tối giản nên a/b=1/3

Tick đi,mất công lắm chứ