Question

Tìm x biết:

a) \(\frac{4}{7}\) nhân x - \(\frac{2}{3}\) = \(\frac{1}{5}\)              b) \(\frac{2}{9}\) + \(\frac{7}{8}\) nhân x = \(\frac{1}{3}\)

Answer 1

a.

\(\frac{4}{7}x-\frac{2}{3}=\frac{1}{5}\)

\(\frac{4}{7}x=\frac{1}{5}+\frac{2}{3}\)

\(\frac{4}{7}x=\frac{3+10}{15}\)

\(\frac{4}{7}x=\frac{13}{15}\)

\(x=\frac{13}{15}\div\frac{4}{7}\)

\(x=\frac{13}{15}\times\frac{7}{4}\)

\(x=\frac{91}{60}\)

b.

\(\frac{2}{9}+\frac{7}{8}x=\frac{1}{3}\)

\(\frac{7}{8}x=\frac{1}{3}-\frac{2}{9}\)

\(\frac{7}{8}x=\frac{3-2}{9}\)

\(\frac{7}{8}x=\frac{1}{9}\)

\(x=\frac{1}{9}\div\frac{7}{8}\)

\(x=\frac{1}{9}\times\frac{8}{7}\)

\(x=\frac{8}{63}\)

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