You need to know these two formulas:
For example,
L(t)=9-0.5t
t=time in hours,
L(t)=length of candle at time t
(A) substitute t=1,2,3,4,5,6 respectively to get
(1,8.5)
(2,8)
(3,7.5)
(4,7)
(5,6.5)
(6,6)
(B) it is a function because none of the x-values duplicate, (nor the y-values).
(C) If the rate changes to 0.45 "/hr, the relation is still linear.
All linear function with finite slope are functions.
Without needing fancy formulas, we can conclude that after 10 years, half of the substance will be left. So, we can make our own formula:
amount remaining = 1 / 2^(years/10)
So, after 5 years
amount remaining = 1 / 2^(5/10)
amount remaining = 1 / 2^(.5)
amount remaining = 1 /
<span>
<span>
<span>
1.414213562
</span>
</span></span><span>amount remaining = 0.70711 * 20 grams
</span><span><span><span><span>amount remaining = </span>14.1421356237 grams
</span></span></span>
He spent $9.50 in total. To find this answer, you write the equation 2(9.95) + 3(1.20). You would distribute getting 5.90 + 3.60= $9.50.
