Answer:
2 hours: 3968 <u>[I don't understand the $ sign in the answer box]</u>
At midnight: 12137
Step-by-step explanation:
The bacteria are increasing by 15% every hour. So for every hour we will have what we started with, plus 15% more.
The "15% more" can be represented mathematically with (1 + 0.15) or 1.15. Let's call this the "growth factor" and assign it the variable b. b is (1 + percent increase).
Since this per hour, in 1 hour we'll have (3000)*(1.15) = 3450
At the end of the second hour we're increased by 15% again:
(3450)*(1.15) = 3968.
Each additional hour add another (1.15) factor, If we assign a to be the starting population, this can be represented by:
P = a(1.15)^t for this sample that increase 15% per hour. t is time, in hours.
If a represents the growth factor, and P is the total population, the general expression is
P = ab^t
Using this for a = 3000 and b = 1.15, we can find the total population at midnight after starting at 2PM. That is a 10 hour period, so t = 10
P = (3000)*(1.15)^10
P = 12137
The total area of pool and border = 361 square feet.
Length of square pool = x
Length of square pool plus border = (x + 1 +1 ) = x + 2
There is 1 foot length on each side on the x length.
The other length of the square pool and border = (x + 2)
Area = (x+2)(x+2)
(x + 2)(x +2) = 361. Let A = x +2
A*A = 361
A² = 361 Take square root of both sides
A = √361
A = 19
A = x + 2 = 19
x = 19 - 2
x = 17
Area of square pool = x*x = 17*17 = 289
Area of the pool = 289 square feet.
Answer:
curtiss can buy 7 pounds of pistachios
Step-by-step explanation:
5 cappuccinos x $5 = 25, 32 - 25=7
2x + 3y = 9
x + 5y = 8....multiply by -2
----------------
2x + 3y = 9
-2x - 10y = -16 (result of multiplying by -2)
---------------add
-7y = - 7
y = -7/-7
y = 1
x + 5y = 8
x + 5(1) = 8
x + 5 = 8
x = 8 - 5
x = 3
solution is (3,1)
