Answer:
C?
Step-by-step explanation:
Sorry I tried im dumb
Answer:
w^2 + 5w = 300
Step-by-step explanation:
A= length x width
A =300
Width = w
length = w + 5
Therefore
300 = (w) x (w + 5)
300 = w^2 + 5w
w^2 + 5w = 300
Answer:
Step-by-step explanation:
If Thaddeus drives the whole 16 hours, the distance between them is ...
distance = speed · time
distance = 20 mi/h · 16 h
distance = 320 miles.
It is 45 miles more than that. For each hour that Ian drives, their separation distance increases by (25 mph -20 mph)·(1 h) = 5 mi. Then Ian must have driven ...
(45 mi)/(5 mi/h) = 9 h
The rest of the 16 hours is the time that Thaddeus drove: 7 hours.
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Let x represent the time Ian drives. Then 16-x is the time Thaddeus drives. Their total distance driven is ...
distance = speed · time
365 mi = (25 mi/h)(x) + (20 mi/h)(16 h -x)
45 mi = (5 mi/h)(x) . . . . . . . . subtract 320 miles, collect terms
(45 mi)/(5 mi/h) = x = 9 h . . . . . . divide by the coefficient of x
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<em>Comment on the solution</em>
You may notice a similarity between the solution of this equation and the verbal discussion above. (That is intentional.) It works well to let a variable represent the amount of the highest contributor. Here, that is Ian's time, since he is driving at the fastest speed.
This question is the application of differential eqns in order to derive a model for the temperature dependence with time. Actually, a general equation has already been derived for this type of cases. This equation is known as the Newton's Law of Cooling. The equation is
(T - Ts) / (To -Ts) = e^(-kt)
where T is the the temperature at any time t
Ts is the surrounding temperature
To is the initial temperature
k is the constant
t is the time
several assumptions have been made to arrive at this form, i suggest you trace the derivation of the general formula.
First we need to look for k using the initial conditions that is @t = 1.5 min, T = 50 F
substituting we get a k = 0.2703
therefore @ t = 1 min, T = 55.79 F
@ T = 15 F the time required is 9.193 min.
Answer:
8)
Step-by-step explanation
Its 8 because 2 x 4 = 8, or
2 x 2 x 2 x 2 = 8.
