Answer:
day 0, day 120
Step-by-step explanation:
You want to find the value of x that makes both y-values be the same:
y = y
30x +10 = -x^2 +150x +10
x^2-120x = 0 . . . . subtract the right side of the equation
x(x -120) = 0 . . . . . factor
Values of x that make this true are x=0 and x=120.
The same number of each car was sold on day 0 and day 120.
