a) x=16
b)x=5
c)x=1
Câu cuối ko bt tính có đúng hông?! Nếu sai choa mk "Sỏ ri"nhá!!!
Bài 1
a/
\(\frac{4}{5}=\frac{x}{20}\)
Quy đồng, ta có : \(\frac{4}{5}=\frac{16}{20}\Rightarrow x-16\)
b/ \(\frac{x}{7}=\frac{30}{42}\)
Rút gọn, ta được : \(\frac{30}{42}=\frac{5}{7}\Rightarrow x=5\)
c/ \(\frac{18}{5}\times x=\frac{9}{7}:\frac{5}{14}\)
\(\frac{18}{5}\times x=\frac{18}{5}\)
\(\Rightarrow x=1\)
c,
\(\frac{18}{5}\cdot x=\frac{9}{7}\div\frac{5}{14}\)
\(\Rightarrow\frac{18}{5}\cdot x=\frac{18}{5}\)
\(\Rightarrow x=1\)
vậy_
\(a,\frac{4}{5}=\frac{x}{20}\)
\(\frac{16}{20}=\frac{x}{20}\)
\(\Rightarrow x=16\)
\(b,\frac{x}{7}=\frac{30}{42}\)
\(\frac{x}{7}=\frac{5}{7}\)
\(\Rightarrow x=5\)
\(c,\frac{18}{5}×x=\frac{9}{7}:\frac{5}{14}\)
\(\frac{18}{5}×x=\frac{9}{7}×\frac{14}{5}\)
\(\frac{18}{5}×x=\frac{18}{5}\)
\(x=\frac{18}{5}:\frac{18}{5}\)
\(x=\frac{18}{5}×\frac{5}{18}\)
\(x=1\)
\(a,\frac{4}{5}=\frac{x}{20}\)
\(\frac{4}{5}=\frac{4\times4}{5\times4}=\frac{16}{20}\)
\(x=\frac{16}{20}\)
