Answer:
first term a=4
Step-by-step explanation:
Sum of the first 6 terms S6 = 15624
common ratio r= 5
n= 6
first term a=?
Formula: S6= a(r^n-1)/r-1
15624 = a( 5^6-1)/5-1
15624 = a(15625-1)/4
15624= a( 15624)÷4
15624= 15624a÷4
Cross multiply
15624×4 = 15624a
62496 = 15624a
divide both sides by 15624
62496÷15624 = 15624a÷15624
4 = a
a= 4
Answer:
There ya go
Step-by-step explanation:
Ok so we can see for every 2 cups of medium coffee, the balance goes down 5.30$. So that means that for every coffee, her balance goes down 2.65$. Solving for the x-intercept means how many medium coffees can I get until my balance is 0. First, we have to find the y-int so it's easy. The slope is -2.65 because for every medium coffee, her balance goes down 2.65$. So we have y=-2.65x+b. Plugging in any point, I choose (4,14.40), we get 14.4 = -2.65 × 4 +b. Solving for b we get 25 for the y intercept, meaning the equation is y = -2.65x + 25 . To find the x intercept, we set y=0. So we have 0 = -2.65x+25. Solving for x we get approx. 9.4. We can't have decimals so we round down to 9. So the x int is ≈ 9.4 meaning we can only buy 9 coffee and have a little extra. But, if the problem said how many more coffees can she get, then here is how we do it. Since she already got 4 coffees, and the max is 9, we do 9-4 and we get 5, so she can buy 5 coffeed more.
Answer:

Step-by-step explanation:
<u>Exponential Growth
</u>
The natural growth of some magnitudes can be modeled by the equation:

Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.
The initial number of bacteria is Po=40 and it doubles (P=2Po) at t=20 min. With that point we can find the value of r:

Simplifying:

Solving for 1+r:
![1+r=\sqrt[20]{2}](https://tex.z-dn.net/?f=1%2Br%3D%5Csqrt%5B20%5D%7B2%7D)

The exponential function that models the situation is:

Answer:
D
Step-by-step explanation:
it states that the snikholes are from underneath when the soil it lose