Thread: Intersection of curves

The line y=2x- 3 intersects the curve y=x^2+x-15 at the points

(a)(3,3)and(4,5)
(b)(-3,-9)and(4,5)
(c)(3,3)and(-4,-11)
(d)(-3,-9)and(-4,-11).

Originally Posted by bobby77

The line y=2x- 3 intersects the curve y=x^2+x-15 at the points

(a)(3,3)and(4,5)
(b)(-3,-9)and(4,5)
(c)(3,3)and(-4,-11)
(d)(-3,-9)and(-4,-11).

At a point of intersection:

,

so:



Now trying the candidates for , we find that , satisfies
this equation as does , so (b) must be the answer (assuming the
's are OK which I suppose we can).

RonL