Miranda wrote:Umm, i know, nothing, i guess...

I missed the term we started algebra, then came to a different school where they were further on at it than i ever was so i havent a clue, here's a question, and how i worked on it:

xsquared + ysquared = 10

2x+y=-5

2x=-5+y

2x-+5=-y

-2x+-5=y

y=-2x+-5

xsquared + (-2x+-5)squared = 10

im stuck

Hang on which part is the question and which part is your workings out?

I am presuming the question is, find x and y given that

x^2+y^2=10 and 2x+y=5 ?

Square 2x+y =5

So you get 4x^2+y^2=25

So you now have x^2+y^2=10 and 4x^2+y^2=25 . These are called simultaneous equations and to find the answer you subtract one from the other.

Now you can write it as a straightforward substitution

4x^2+y^2=25

minus x^2+y^2=10

___________________

3x^2=15

therefore x=sqrt 5 and y=sqrt 5

or you might like this way better

rearrange the equations so you have zero on the right of each and put them equal to each other

4x^2+y^2-25=0

x^2+y^2-10=0

therefore

4x^2+y^2-25=x^2+y^2-10

and solve from there