X = 1 hr lessons and y = 1/2 hr lessons
x + y = 35......y = 35 - x
40x + 25y = 1115
40x + 25(35 - x) = 1115
40x + 875 - 25x = 1115
40x - 25x = 1115 - 875
15x = 240
x = 240/15
x = 16 <=== there are 16 one-hr lessons
and 19 half-hr lessons
To calculate the remaining caffeine, we use the radioactive decay formula which is expressed as An = Aoe^-kt where An is the amount left after t time, Ao is the initial amount and k is a constant we can calculate from the half-life information. We do as follows:
at half-life,
ln 1/2 = -k(6)
k = 0.12/hr
An = 80e^-0.12(14)
An = 15.87 mg
Answer: when you graph it, it opens down so it will have a maximum
Step-by-step explanation:
Answer: 4.8 miles
Step-by-step explanation:
6/55 = x/44
55x = 6(44)
55x = 264
x = 264/55 = 4.8 miles
Answer:
she had 16
16
She got c
16 + c
She now has 32
16 + c = 32
I don't know if that's the exact answer, but basically, 16 needs to be added to c, and it needs to equal 32.
Hope this helps! :)