Suppose a 9 minute overseas call costs $6.48 and a 19 minute call costs $13.68. what is the cost, c, of a call of m minutes duration? write a equation to model the cost.

9m = 6.48

Divide both sides by 9:

m = 0.72

19m = 13.68

Divide both sides by 19:

m = 0.72

So a one minute call costs 72 cents. We can now set up an equation like this:

c = 0.72m

the answer is 200

step-by-step explanation:

the way the question is worded, it seems to imply the $264 interest is simple interest, not compound interest.

the simple interest for 2 years is $264; the simple interest for 1 year is $132.

$132 interest on a $600 investment means an interest rate of (132/600)*100 = 22%.

the value of $200 at 22% interest compounded annually for three years is

200%281.22%29%5e3

the amount of interest is that value, minus the original $200.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)