Question

Ma puteți ajuta va rog?

Answer 1

varianta 1
imparti cu y si numaratorul si numitorul
(x./y+2)/(2x/y +1)=5/4
x/y=t
(t+2)/(2t+1)=5/4
4t+8=10t+5
8-5=10t-4t
3=6t
6t=3
t=3/6=1/2
x/y=1/2


y/x=2/1=200/100=200%




varianta 2, mai rapida
aplicam prop. fundam. a proportiilor
4x+8y= 10x+5y
3y=6x
y=2x
impartim prin x
 y/x=2=2/1
 atunci x/y=1/2


din y/x=2/1⇒y/x=200/100=200%