Answer:
-170
Step-by-step explanation:
First, you would substitute 2 and 4 for a and b. 4 times 2 + 3(4 - 62) - 2 times 2 = ?
Then, do 4 times 2 (8), 3(4-62)=3(-58)
8 + -174 - 4 = -170
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.
Photomath is a good one. So is KhanAcademy, but I don't know if they have an app version of the website.
If you use FOIL to multiply these two brackets, it will lead you what is exactly written (xa+xb+ya+yb)
so it is correct
A