Answer:
That depends on which operations you want to do first. The order of operations affect to outcome of the equation.
In this case:
15 - (3 x 4) + 9 = 12
9x^3-39x^2-38x+40=(3x-2)(3x+4)(x-5) by synthetic division
Thus roots are -4/3, 2/3, 5
Slope = (y₂-y₁)/(x₂-x₁)
by making (x₁,y₁) = (-2,2) and (x₂,y₂) = (5,3)
∴The slope = (3-2)/(5 - -2) = 1/7
