Question

Tìm a,b Biết

\(\frac{a}{b}\)=\(\frac{2}{5}\)và a-b=30

Answer 1

\(\frac{a}{b}=\frac{2}{5}\Rightarrow\frac{a}{2}=\frac{b}{5}=\frac{a-b}{2-5}=\frac{30}{-3}=-10\)

\(\Rightarrow\frac{a}{2}=-10\Rightarrow a=-20\)

\(\frac{b}{5}=-10\Rightarrow b=-50\)

Answer 2

a/b=2/5 => a/2=b/5 =>a-b/2-5 =30/-3=-10

a/2= -10 =>a= -20

b/5= -10 =>b =-50

=>a=-20     b=-50