Question

tìm x;y

x+y=x.y=y:x (y khác 0)

Answer 1

Ta có:

xy = x:y

=> y²= x:x = 1

=> y = 1 hoặc y= -1

y= 1 => x+1 = x (vô lý)

y= - 1 => x-1 = -x

=>x = \(\frac{1}{2}\)

Answer 2

\(\text{Tìm }x\text{ ; }y\)

\(x+y=x\cdot y=y\text{ : }x\left(y\text{ khác }0\right)\)

\(\text{Ta có : }\)

\(y\cdot x=y\text{ : }x\)
\(\Rightarrow\text{ }y^2=x\text{ : }x=1\)\(\Rightarrow\text{ }y=1\text{ hoặc }y=-1\)

\(\text{Mà : }\)

\(y=1\text{ }\Rightarrow\text{ }x+1=x\left(\text{ Thì không thể }\right)\)

\(y=-1\text{ }\Rightarrow\text{ }x-1=-x\)

\(\Rightarrow\text{ }x=\frac{1}{2}\)