Question

tìm phân số a/b

a)a/b-1/2=4/7

b)a/b-1/4-1/3=5/6

Answer 1

a, \(\dfrac{a}{b}=\dfrac{4}{7}+\dfrac{1}{2}=\dfrac{8+7}{14}=\dfrac{15}{14}\)

b, \(\dfrac{a}{b}=\dfrac{5}{6}+\dfrac{1}{4}+\dfrac{1}{3}=\dfrac{10+3+4}{12}=\dfrac{17}{12}\)

Answer 2

\(a:\dfrac{a}{b}-\dfrac{1}{2}=\dfrac{4}{7}\\ \dfrac{a}{b}=\dfrac{4}{7}+\dfrac{1}{2}\\ \dfrac{a}{b}=\dfrac{8}{14}+\dfrac{7}{14}\\ \dfrac{a}{b}=\dfrac{15}{14}\\ b:\dfrac{a}{b}-\dfrac{1}{4}-\dfrac{1}{3}=\dfrac{5}{6}\\ \dfrac{a}{b}-\left(\dfrac{1}{4}+\dfrac{1}{3}\right)=\dfrac{5}{6}\\ \dfrac{a}{b}-\dfrac{7}{12}=\dfrac{5}{6}\\ \dfrac{a}{b}=\dfrac{5}{6}+\dfrac{7}{12}\\ \dfrac{a}{b}=\dfrac{17}{12}\)

Answer 3

a )

\(\dfrac{a}{b}-\dfrac{1}{2}=\dfrac{4}{7}\\ \dfrac{a}{b}=\dfrac{4}{7}+\dfrac{1}{2}\\ \dfrac{a}{b}=\dfrac{15}{14}\)

b) 

\(\dfrac{a}{b}-\dfrac{1}{4}-\dfrac{1}{3}=\dfrac{5}{6}\\ \dfrac{a}{b}-\dfrac{-1}{12}=\dfrac{5}{6}\\ \dfrac{a}{b}=\dfrac{5}{6}+\dfrac{-1}{12}\\ \dfrac{a}{b}=\dfrac{3}{4}\)