How can graphing be applied to solving systems of non linear ? how is the final solutions appear on the graph?

Line cd passes through points c(1, 3) and d(4, –3). if the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b? –5 –2 1 5

With alll of except for the 2 that i did already

What is the distance from zero if a quadratic function has a line of symmetry at x=-3 and a zero at 4