I have attached the graph of both equations for values between x=-4 and x=3 but it's impossible to find exact points of intersection by looking at the graph for y = 3x² + 2x - 5 (blue curve) and y = 2x +10 (red line).

I suggest you do it by solving system by substitution method.

Also finding when exact 3x² + 2x - 5 equals to 0 by looking at graph is not possible. It can be seen from graph that one solution is x=1 but other solution is somewhere between -1,5 and -2. So that too equation must be solved.

Graph for both tasks is useless here.