Where do you find a solution to a system of inequality ?

To solve a system of inequalities, graph each linear inequality in the system on the same x-y axis by following the steps below:

Isolate the variable y in each linear inequality.

Draw and shade the area above the borderline using dashed and solid lines for the symbols > and ≥ respectively.

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50