SOLUTION: If possible solve the nonlinear system of equations with Method of substitution. 2x-y=0 2xy=4 Please help. I got: x=+-1 y=+-2 No Solution?

Algebra ->  Linear-equations -> SOLUTION: If possible solve the nonlinear system of equations with Method of substitution. 2x-y=0 2xy=4 Please help. I got: x=+-1 y=+-2 No Solution?       Log On


   

Question 925853: If possible solve the nonlinear system of equations with Method of substitution.
2x-y=0
2xy=4
Please help. I got:
x=+-1
y=+-2
No Solution?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
2x-y=0....eq.1
2xy=4+....eq.2
________________
start with 2x-y=0....eq.1, solve for x
2x=y
x=y%2F2...substitute in eq.2
2%28y%2F2%29y=4+....eq.2
cross%282%29%28y%2Fcross%282%29%29y=4+
y%2Ay=4+
y%5E2=4+
y=sqrt%284%29+
solutions:
y=2 or y=-2
go to eq.1 or 2, substitute y

2x-y=0....eq.1 if y=2
2x-2=0
2x=2
x=2%2F2
x=1
or
if y=-2
2x-%28-2%29=0
2x%2B2=0
2x=-2
x=-2%2F2
x=-1
solutions to the system:
x=1,y=2
or
x=-1,y=-2
2x-y=0....eq.1
2xy=4+....eq.2