$$\frac{5}{4x-4} = \frac{10}{5y-4} \Rightarrow 5(5y-4)=10(4x-4) \Rightarrow 25y-20=40x-40 \\ \Rightarrow 25y=40x-20 (*)$$
$$ \frac{2} {3x+2} = \frac{3}{5y - 3.5} \Rightarrow 2(5y-3.5)=3(3x+2) \Rightarrow 10y-7=9x+6 \\ \Rightarrow 10y=9x+13 \Rightarrow y=\frac{9x+13}{10}$$
$$(*) : 25 \frac{9x+13}{10}=40x-20 \Rightarrow 25(9x+13)=400x-200 \\ \Rightarrow 225x+325=400x-200 \Rightarrow 175x=525 \Rightarrow x=\frac{525}{175}=3$$
Berechne jetzt noch das y.