Thread: Solving Quadratic Systems of Equations

I have this system:




And I have to find the intersecting points of the two equations by using substitution and only substitution.

I solved the bottom equation for y getting . From there, this is how I progressed:





Combining like terms:



Pulling out a 3 gives me:



From here, I'm not sure what to do. Am I on the right track or am I doing this completely wrong? If the latter, please explain to me where I made an error so it doesn't happen again.

Thank you.

Hello,

Originally Posted by mathgeek777

I have this system:




And I have to find the intersecting points of the two equations by using substitution and only substitution.

I solved the bottom equation for y getting . From there, this is how I progressed:





Combining like terms:



Pulling out a 3 gives me:



From here, I'm not sure what to do. Am I on the right track or am I doing this completely wrong? If the latter, please explain to me where I made an error so it doesn't happen again.

Thank you.

Little typo in red, not changing what follows.

Well, I don't see any mistake that far.

I've substituted y, and I also get complex solutions :-)

Since I couldn't find any obvious real solution, I put it down as no real solutions, checked the back of the book, and it is indeed no real solutions.

Thanks for the help.