help me solve system algebraically
Xsquared + Ysquared = 5
2Xsquared + Y = 0

Question

help me solve system algebraically
Xsquared + Ysquared = 5
2Xsquared + Y = 0

anonymous · Answer

$$x^2+y^2=5$$$$2x^2+y=0$$
$y=-2x^2$ substitute in to first one get 
$$x^2+(-2x^2)=5$$ so $5x^2=5$ and so $x=\pm1$

anonymous · Answer

this makes $y=-2$ by substitution

ajprincess · Answer

$x^2+y^2=5$
$2x^2+y=0$
$y=-2x^2$
Substitute it in the first equation
$x^2+(-2x^2)^2=5$
$x^2+4x^4=5$
$4x^4+x^2-5=0$

anonymous · Answer

man did i mess that up!!

anonymous · Answer

how did you acquire 5xsquared  = 5 from xsquared (-2xsquared)= 5

anonymous · Answer

i cant really tell which one is right, i need to be able to graph to check if its correct

anonymous · Answer

i need the poiiinntttssss to plot

anonymous · Answer

You just need to factor the equation ajprincess has to lead you to your points you need:
$$4x ^{4}-4x ^{2}+5x ^{2}-5=0$$

This factors into $$4x ^{2}\left( x ^{2} -1\right)+5\left( x ^{2}-1 \right)=0$$

which in turn becomes 
$$\left( 4x ^{2} +5\right)\left( x ^{2} -1\right)=0$$

Then only the the second factor can be solved over the real numbers.  Once you find $$x=\pm1$$

Go back to either of your two equations and solve for y by substituting your values of x.