Using a system of equations, it is found that they will have the same profit after 2 days. The solutions x = -5 is non-viable as time measures are non-negative.
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the equations are:
P(x) = -x² + 9x + 10.
Q(x) = 12x.
They have the same profit when:
P(x) = Q(x)
-x² + 9x + 10 = 12x
x² + 3x - 10 = 0
(x + 5)(x - 2) = 0
x = -5 or x = 2.
They will have the same profit after 2 days. The solutions x = -5 is non-viable as time measures are non-negative.
More can be learned about a system of equations at https://brainly.com/question/24342899