Question

Timf x,y biết x(x-y)=3/10 và y(x-y) = -3/50

Answer 1

\(x\left(x-y\right)=\frac{3}{10};y\left(x-y\right)=-\frac{3}{50}\)

\(\Rightarrow\frac{x\left(x-y\right)}{y\left(x-y\right)}=\frac{\frac{3}{10}}{\frac{-3}{50}}\Rightarrow\frac{x}{y}=\frac{3}{10}.\frac{50}{-3}=-5\)

\(\Rightarrow x=-5y\)(1)

Thay (1) vào

\(x\left(x-y\right)=\frac{3}{10}\Rightarrow-5y\left(-5y-y\right)=\frac{3}{10}\)

\(\Rightarrow30y^2=\frac{3}{10}\Leftrightarrow y^2=\frac{3}{10}.\frac{1}{30}=\frac{1}{100}\Rightarrow y=\orbr{\begin{cases}\frac{1}{10}\\-\frac{1}{10}\end{cases}}\)

\(\Rightarrow x=\orbr{\begin{cases}\frac{1}{10}.-5=-\frac{1}{2}\\-\frac{1}{10}.-5=\frac{1}{2}\end{cases}}\)

Answer 2

x*(x-y)=3/10

y*(x-y)=-3/50

=>x*(x-y)-y*(x-y)=3/10-(-3/50)

=>(x-y)*(x-y)=15/50+3/50=18/50=9/25

=>x-y=(3/5;-3/5)

+)Nếu x-y=3/5=>x=1/2;y=-10

+)Nếu x-y=-3/5=>x=-1/2;y=10

Answer 3

Phạm Tuấn Đạt ơi sao suy luôn ra đc 30y^2 z ?