negative multiplied by positives = negative numbers
3 x 5 = -15
negative multiplied by a negative = a positive number
-3 x -2y = +6y
so combine both gets -15 +6y
or a better way to write it is 6y-15
14.99n+4.99 represents the cost of n cds
(14.99x3) + 4.99 =
34. 97 + 4.99= $39.97- 0.1= $39.96
3 CD s cost $39.96
Answer:
It would take 24 minutes for the element to decay to 50 grams
Step-by-step explanation:
The equation for the amount of the element present, after t minutes, is:

In which Q(X) decays radioactively with a half life of 12 minutes.(0) is the initial amount and r is the rate it decreases.
Half life of 12 minutes
This means that 
So








If there are 200 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to decay to 50 grams?
This is t when Q(t) = 50. Q(0) = 200.








It would take 24 minutes for the element to decay to 50 grams