Hello,

If one point is on the x-axis, then y=0. So the point (3,0) is a point on the curve.

If it "touches" the x axis at x=9/4, it means that the x axis is tangent to the curve at this point.

This means two things :

- the derivative at this point is 0.

Mr F adds: If you haven't done calculus, this means that there's a turning point at this point.
- the point (9/4,0) is a point on a curve.

Mr F adds: In case you haven't done calculus ..... when a cubic function has a turning point at the x-intercept ( , 0) this means that is a factor of the cubic.
Now, substitute all this information in the equation. It should give you 3 equations with 3 unknowns.