Question

Tìm phân số a/b biết :

a,  3/4 - 1/6 - a/b = 1/2

b,  a/b x 1/4 x 2/5 = 1/7

c,  1/3 : a/b = 2/3 : 4/3

Answer 1

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

\(\frac{7}{12}-\frac{a}{b}=\frac{1}{2}\)

\(\frac{a}{b}=\frac{7}{12}-\frac{1}{2}\)

\(\frac{a}{b}=\frac{1}{12}\)

b) \(\frac{a}{b}\times\frac{1}{4}\times\frac{2}{5}=\frac{1}{7}\)

\(\frac{a}{b}\times\frac{1}{10}=\frac{1}{7}\)

\(\frac{a}{b}=\frac{1}{7}:\frac{1}{10}\)

\(\frac{a}{b}=\frac{10}{7}\)

c) \(\frac{1}{3}:\frac{a}{b}=\frac{2}{3}:\frac{4}{3}\)

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

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

\(\frac{a}{b}=\frac{3}{2}\)

Answer 2

a) 1/12

b) 10/7

c) 2/3

mk ko chắc là đúng đâu nha bn

Answer 3

a) 1/12

b) 10/7

c) 3/2