You have two choices.
The minimum possible cost to operate your bat factory for a day is $390,
and there are two quantities of bats that both cost that much.
One possibility:
Produce no bats at all per day. Zero. Nada. None.
Cost = 0.06(0)² - 7.2(0) + 390 = $390 per day.
The other choice:
Produce 120 bats per day.
Cost = 0.06(120²) - 7.2(120) + 390
= 0.06(14,400) - 7.2(120) + 390
= 864 - 864 + 390
= $390 per day.
If you produce any other number of bats in a day ... more than zero
but not 120 ... then it will cost you more than $390 to operate the factory
that day.
Sqrt(1-3x)=x+3
[sqrt(1-3x)]^2=(x+3)^2
1-3x=(x+3)(x+3)
1-3x=x^2+6x+9
-3x=x^2+6x+8
0=x^2+9x+8
The answers are -1 and -8 BUT, we have to plug them back into the original equation to make sure we don't get a negative under the square root sign.
After doing this, we realize that only -1 works, so the answer is x=-1
Sorry that this took forever to answer. I was thinking of a good way to explain this, and if you need any further explanation, message me:)
Best wishes:)
21^2/0.219 = 2013.69863
2 significant figures are the 20, so the answer is 2000
Answer:
C.
Step-by-step explanation:
Negative exponents on the top is equivalent to them being positive in the bottom.