In order to make the whole problem easier, you would have to get all the numbers to have the same denominator which would be 60.
1/10 * 6 = 6/60
1/4 * 15 = 15/60
1/5 * 12 = 12/60
2/15 * 4 = 8/60
Now that all the numbers have the same denominator, you would add them to get 41/60.
In conclusion, the answer would be D.
SOLUTION
We have been given the equation of the decay as

So we are looking for the time
Plugging the values into the equation, we have

Taking Ln of both sides, we have

Hence the answer is 4308 to the nearest year
300 messages would have to be sent or received in order for the plan to cost same each month.
Step-by-step explanation:
Given,
Cost per month = $30
Per text sent or received charges = $0.10
Let,
x be the number of texts sent or received.
A(x) = 0.10x+30
A comparable plan costs = $60 per month
Text messages are unlimited.
B(x) = 60
For the two plans to cost equal;
A(x) = B(x)

Dividing both sides by 0.10

300 messages would have to be sent or received in order for the plan to cost same each month.
Keywords: function, addition
Learn more about functions at:
#LearnwithBrainly
Y=12 because the triangles have proportional side lengths
Answer:
d = 3/7 = 0.429
d = 1
Step-by-step explanation: