Answer:
The solutions are: x=6. x=-4 and x=-8.
Explanation:
The solution to the system of the equation is going to be given by the points where the graphs of:
y = x3 + 6x2 - 40x AND y = 192 intercept.
By looking at the graph, we can deduce they intercept at three points:
(-8, 192), (-4, 192) and (6, 192).
Another way to verify this, is by solving the following system of equations:
x3 + 6x2 - 40x - 192 = 0
Factorizing, we get:
(x-6)(x+4)(x+8) = 0
Where we can clearly see that the solutions are: x=6. x=-4 and x=-8.