How do you solve the system 10y=x^2 and x^2-6=-2y?

1 Answer
Jul 15, 2016

We have two solutions (-sqrt5,1/2) and (sqrt5,1/2)

Explanation:

As 10y=x^2 and x^2-6=-2y, putting value of x^2 from first equation into second we get

10y-6=-2y or

10y+2y+6-6=-2y+2y+6 or

12y=6 or

y=6/12=1/2.

Hence, x^2=10×1/2=5 or

x^2-5=0 or

x^2-(sqrt5)^2=0 or

(x-sqrt5)(x+sqrt5)=0

Hence, either x-sqrt5=0 i.e. x=sqrt5

or x+sqrt5=0 i.e. x=-sqrt5

Hence we have two solutions (-sqrt5,1/2) and (sqrt5,1/2)