Question

Help!Am nevoie de ajutor!Dau coroana!!!​

Answer 1

$\it \dfrac{a}{5a+b+c+d}=\dfrac{b}{a+5b+c+d}\Rightarrow a^2+5ab+ac+ad=5ab+b^2+bc+bd\Rightarrow\\ \\ \\ \Rightarrow (a^2-b^2)+(ac-bc)+(ad-bd)=0\Rightarrow(a-b)(a+b)+c(a-b)+d(a-b) =0\Rightarrow\\ \\ \\ \Rightarrow (a-b)(a+b+c+d)=0 \Rightarrow a-b=0 \Rightarrow a=b$

Analog ⇒ a=c,  a=d