Question

\(\frac{a}{b}\cdot\frac{c}{d}=0\)khi nao

Answer 1

\(\frac{a}{b}.\frac{c}{d}\)khi \(\orbr{\begin{cases}\frac{a}{b}=0\\\frac{c}{d}=0\end{cases}}\)

đúng nha

Answer 2

\(\frac{a}{b}=0;\frac{c}{d}=0;\frac{a}{b},\frac{c}{d}=0\)

Answer 3

\(\frac{a}{b}\cdot\frac{c}{d}=0\)

\(\Leftrightarrow\orbr{\begin{cases}\frac{a}{b}=0\\\frac{c}{d}=0\end{cases}}\)

1 trong 2 cái = 0 là ok :))