Answer:
the answer is below
Step-by-step explanation:
accidently made b to x
Answer:
<h2><em><u>X = 28</u></em></h2>
Step-by-step explanation:
14 × 2 = X
=> <em><u>28 = X (Ans)</u></em>
Answer:

Step-by-step explanation:
The equation for exponential decay function is given as:

where:
D(t)= difference in temperature t=time
r=rate of change
a =initial value of the temperature
From the given problem:
Initial Temperature,a=50°C
Rate of Decay,r=
Therefore the function for the difference in temperature is given as:


We can convert
to decimal and write the function as:

Well, the first thing we need to do is divide 10 by 4. These teo numbers are the number of pens, and cost of them. So,
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10 / 4 = 2.5
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Now we have to use the answer we got, 2.5 which is the cost of 1 pen, and multiply it by 7.
================================
2.5 x 7 = 17.5
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This means that 7 pens cost <span>£</span>17.5