Question

Tìm a/b 5/9 x a/b -11/21 = 4/21

Answer 1

5/9 x a/b -11/21 = 4/21

\(\dfrac{5}{9}\times\dfrac{a}{b}=\dfrac{4}{21}+\dfrac{11}{21}\)

\(\dfrac{5}{9}\times\dfrac{a}{b}=\dfrac{15}{21}=\dfrac{5}{7}\)

\(\dfrac{a}{b}=\dfrac{5}{7}:\dfrac{5}{9}\)

\(\dfrac{a}{b}=\dfrac{5}{7}\times\dfrac{9}{5}\)

\(\dfrac{a}{b}=\dfrac{9}{7}\)

Answer 2

5/9.a/b=4/21+11/21

5/9.a/b=15/21

a/b=15/21:5/9

a/b=15/21.9/5

a/b=9/7

=> a=9 ; b=7