\(\frac{x.\left(x-y\right)}{y.\left(x-y\right)}=\frac{3}{10}:-\frac{3}{50}=-5=\frac{x}{y}\)
\(x=-5y\Rightarrow-5y\left(-5y-y\right)=\frac{3}{10}\Rightarrow30y^2=\frac{3}{10}\Rightarrow y=\frac{1}{10}hoặcy=-\frac{1}{10}\)
với y=1/10 => x=-5.1/10=-1/2
với y= -1/10 => x= 1/2
x.(x-y)-y.(x-y)=3/10--3/50
=(x-y).(x-y)=18/50
=(x-y)2=9/25
=(x-y)2=(3/25)2,(-3/25)2
=>x-y=3/25 hoặc -3/25
x.(x-y)=3/10
=>x.3/25=3/10
=>x=3/10:3/25
hoặc x-y=-3/25
tự làm tiếp