Question

3. tìm x

a. x+ \(\dfrac{1}{3}\)=\(\dfrac{1}{2}\)

b. \(\dfrac{5}{3}\) - x =\(\dfrac{4}{7}\)

c. \(\dfrac{4}{7}\). x -\(\dfrac{2}{3}\)=\(\dfrac{1}{5}\)

d.\(\dfrac{2}{5}\): x =-\(\dfrac{1}{4}\)

Answer 1

a) \(x+\dfrac{1}{3}=\dfrac{1}{2}\\ x=\dfrac{1}{2}-\dfrac{1}{3}=\dfrac{1}{6}\)

b) \(\dfrac{5}{3}-x=\dfrac{4}{7}\\ x=\dfrac{5}{3}-\dfrac{4}{7}=\dfrac{23}{21}\)

c) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\\\dfrac{4}{7}.x=\dfrac{1}{5}+\dfrac{2}{3}=\dfrac{13}{15}\\ x=\dfrac{13}{15}:\dfrac{4}{7}=\dfrac{91}{60}\)

d) \(\dfrac{2}{5}:x=\dfrac{-1}{4}\\ x=\dfrac{2}{5}:\dfrac{-1}{4}=\dfrac{-8}{5}\)