Can someone answer this. Please I have to answer this before class ends and that’s at 8:40

Don't know how to find x given these segment lengths

If the discriminant if a quadratic equation is 4 which statement describes the roots?

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.