Question

Dacă a/b=0,(2),atunci 2a/b-2a= .....

Answer 1

[tex]\it \dfrac{a}{b} = 0,(2) \Rightarrow \dfrac{a}{b} = \dfrac{2}{9} \Rightarrow \dfrac{b}{a} = \dfrac{9}{2} \Rightarrow \dfrac{b}{a} = 4,5 \Rightarrow b = 4,5a \ \ \ \ (*) \\ \\ \\ \dfrac{2a}{b-2a} = \dfrac{2a}{4,5a-2a} = \dfrac{2a}{2,5a} = \dfrac{^{4)}2}{\ 2,5}= \dfrac{8}{10} = 0,8[/tex]

Answer 2

a/b=2/9   ⇒    b=9a/2
2a/(9a/2 - 2a)=
2a/(9a/2 - 4a/2)=
2a/(5a/2)=
2a : 5a/2=
2a × 2/5a= 4a/5a=4/5