The <span>minimum number of points through which a line is drawn is 2 points please let me know if im wrong</span>
Alright, so you have the basic formula- good.
You have the A value (400), the interest rate r (7.5% -> .075 in decimal), and the final P value (8500). So, we only need to solve for t.
8500 = (400)(1+.075)^t
/400 /400
21.25 = 1.075^t
logarithms are the inverse of exponents, basically, if you have an example like
y = b^x, then a logarithm inverts it, logy(baseb)=x
Makes sense if you consider a power of ten.
1000 = 10^3
if you put logbase10(1000), you'll get 3.
Anyways, though, to solve the problem make a log with a base of 1.075 in your calculator
log21.25(base 1.075) = t
also, because of rules of change of base (might want to look this up to clarify), you can write this as log(21.25)/log(1.075) = t
Thus, t is 42.26118551.
Rounded to hundredths, t=42.26
Answer:
A=152
K= -Ln(0.5)/14
Step-by-step explanation:
You can obtain two equations with the given information:
T(14 minutes) = 114◦C
T(28 minutes)=152◦C
Therefore, you have to replace t=14, T=114 and t=28, T=152 in the given equation:
Applying the following property of exponentials numbers in (II):
Therefore 
can be written as 
Replacing (I) in the previous equation:
Solving for k:
Subtracting 190 both sides, dividing by -76:
Applying the base e logarithm both sides:
Ln(0.5)= -14k
Dividing by -14:
k= -Ln(0.5)/14
Replacing k in (I) and solving for A:
Dividing by 0.5
A=152
Ht of ceiling = 10 ft which is two-thirds of living rm ceiling
Ht of living rm ceiling = 2/3x = 10 ft
2/3h = 10 ft
2/3h times 3/2 to solve for h = 10 times 3/2
h = 30/2
h = 15 ft
