Question

Giá trị của a thỏa mãn \(\frac{3}{4a}-\frac{4}{a}=\frac{13}{20}\)

Answer 1

\(\frac{3}{4a}-\frac{4}{a}=\frac{13}{20}\)

\(\Rightarrow\frac{3}{4a}-\frac{16}{4a}=\frac{13}{20}\)

\(\Rightarrow\frac{3-16}{4a}=\frac{13}{20}\)

\(\Rightarrow\left(3-16\right).20=13.4a\)

\(\Rightarrow-260=13.4a\)

\(\Rightarrow4a=-20\)

\(\Rightarrow a=-5\)

Answer 2

34a−4a=1320

\(\Rightarrow\frac{3}{4a}-\frac{16}{4a}=\frac{13}{20}\)

\(\Rightarrow\frac{3-16}{4a}=\frac{13}{20}\)

\(\Rightarrow\frac{-13}{a}=\frac{13}{20}\)

\(\Rightarrow\) (-13) . (20) = 13a

\(\Rightarrow\) a = - 20