The function f(x) = 4x - 0.1x2 is used to model the curve of a bridge over a small river, where x is the distance from
one side of the river and the x-axis represents the ground.
The mathematical range for the function is the set of real
numbers. which statement describes the limitations for the reasonable range compared to the mathematical range?

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.