The area of the circle by definition is given by:

For f (r) = 154:

Clearing r we have:

For f (r) = 616:

Clearing r we have:
Answer:
a reasonable domain for f (r) is:
7 <r <14
Common ratio, r = (-125)/625 = -0.2
First term, a = 625
7 term
= ar^6
= 625(-0.2)^6
= -0.04
Answer:
18 years
Step-by-step explanation:
The formula for computing accrued amount A for a principal of P at an interest rate of r(in decimal) compounded n times in a year for t years is given by

Note that r is percentage converted to decimal. So 3% = 3/100 = 0.03
We can rearrange the above equation to:

Taking logs on both sides

This gives

In this particular problem, n = 4, , A= 9600, P = 5600, r =0.03, so r/n = 0.03/4 = 0.0075
1 + r/n = 1+0.0075 = 1.0075
4t = log(9600/5600)/log(1.0075) = log(1.714) / log(1.0075) = 0.234 /0.00325 = 72
t = 72/4 = 18 years
Given that I no not see any explanation in the previos answer, I think you can benefit of this.
Exothermic refers only to the fact that the reaction releases energy in the form of heat when occurs. So, the enthalpy is higher at start and lower and the end.
Seen in this way, you can deduct that the change in enthalpy is negative, which is what the third option says.
Answer:
600 L of 30% proof and 400 L of 80% proof is needed
Step-by-step explanation:
Let the amount of 30% smell proof be x while that of 80% smell proof is y
Then;
x + y = 1000 •••••(i)
Also;
30% of x + 80% of y = 50% of 1000
0.3x + 0.8y = 500 •••••(ii)
From i, x = 1000 - y
Put this into ii
0.3(1000-y) + 0.8y = 500
300 - 0.3y + 0.8y = 500
0.5y = 500-300
0.5y = 200
y = 200/0.5
y = 400 L
But x = 1000 - y
x = 1000 - 400 = 600 L