hi would I solve equations such as
y=-3x+2
and
y=2x^2-7x-4
by factorising or using the quad formula, as I need to find where the above intersect on a graph.
Many thanks
Dave
This is just a simple simultaneous equation. There will of course be 2 intersection points. $\displaystyle y=2x^2-7x-4$ is a parabola and $\displaystyle y=-3x+2$ will intersect it at 2 points.
as $\displaystyle y=y$ then $\displaystyle 2x^2-7x-4=-3x+2$
Therefore, $\displaystyle 2x^2-7x-4=-3x+2=2x^2-4x-6$
$\displaystyle \frac{2x^2-4x-6}{2} = x^2-2x-3$
This is a quadratic, so factorise this equation and it will give you two points for $\displaystyle x$. Put these back into the equation, and you will retrive the values for $\displaystyle y$.