PDA

View Full Version : Need help with this simultaneous equation


gazza123
Nov2-05, 04:15 PM
I've got to solver the simultaneous equations
y = x2 - x - 6
and
x - y + 2 = 0


I've tried it four different times and failed each time. :frown:

Cheers.

PS. x2 = x squared

Saoist
Nov2-05, 04:18 PM
make y the subject of the 2nd one, equate the two, and solve it like a quadratic....?

ie. x+2=x^2-x-6

HallsofIvy
Nov2-05, 05:17 PM
I've got to solver the simultaneous equations
y = x2 - x - 6
and
x - y + 2 = 0
I've tried it four different times and failed each time. :frown:
Cheers.
PS. x2 = x squared

From the second equation, y= x+ 2 so the first equation becomes
x+ 2= x2- x- 6 or x2- 2x- 8= 0.
Solve that equation. That's easy to factor. Once you have x, put it into y= x+ 2 to find the corresponding y.