You will need to look for the x-values of the points where a quadratic graph intersects with a straight line
A suitable line
To find a suitable straight line, rearrange the quadratic equation so that the left-hand side matches the equation of the quadratic graph
The right-hand side will tell you which line to draw
Here is another example
* Graph given= y =x^2 -6x +4
* Equation to solve = x^2 -5x +1 =0
* Rearrange equation = x^2 - 6x +4 = -x + 3
* Line to draw = y = -x +3