Answer:
The insect population after 6 days is of 1639 insects.
Step-by-step explanation:
A population of insects increases at a rate 230 + 8t + 0.9t2 insects per day
This means that 
The population of insects after x days is given by:

So



In which K is the initital population(which is 50). So

After 6 days:

Rounding to the nearest insect, 1639
The insect population after 6 days is of 1639 insects.
12,000,00+ 400,000+ 30,000
Answer:

Step-by-step explanation:
The equation of a quadratic function in vertex form is given by:

Where (h,k) is the vertex.
It was given in the question that the vertex of the parabola is (-1,4).
When we substitute the vertex into the formula we get:

The parabola also passes through (4,19) hence it must satisfy its equation.



We divide both sides by 25 to get:

Hence the quadratic function is:
