Answer:
40-16+10
Step-by-step explanation:
40-16+10= 34
-20+18+18= 28
the greater answer is 40-16+10
Answer:
9 hours
Step-by-step explanation:
According to Newton's laws of cooling
dT/dt = -k(T - A)
Let U = T - A
dU/dT = 1
dU = dT
dt/dt = -kU
dT = -kU(dt)
dU/U = -kdt
On integration
ln(U) = -kt + C
U = Ce^-kt
T - A = Ce^-kt
T(0) = 68
T(5) = 25
68 - 20 = Ce^-k(0)
C = 48
and
25 -20 = 48e^-k(5)
5 = 48e^-5k
e^-5k = 5/48
-5k = ln (5/48)
k = - ln(5/48) / 5
k = - 0.4524
T - 20 = 48e^-0.4524t
When T = 21
21 -20 = 48e^-0.4524t
1 = 48e^-0..4524t
e^-0.4524t = 1/48
-0.4524t = ln (1/48)
t = - ln(1/48) / 0.4524
t = 8.5570
t= 9 hours ( to the nearest hour)
Answer:
8.8
Step-by-step explanation:
first you divide 28/7 (because there are 7 days in the week) you take that number, which is 4 and multiply it was 2.2 to convert the 4 kilograms into pounds.
Hello,
A good method for solving this question is creating an equation to solve for the width of the door.
Let w = the width of the door
Let h = the height of the door
The height (h) is twice the width (2w) and one foot more (+1).
We can make the equation h = 2w + 1
Now, we are given that the height of the door is 7 feet, so h = 7.
We can simply plug in 7 for h in the equation to solve for w.
So, we have h = 2w + 1
7 = 2w + 1
Subtract by 1 on both sides to get:
6 = 2w
Divide by 2 on both sides to get:
w = 3
The width of the door is 3 feet.
However, we should check out answer with the given question to make sure it checks out.
We are given that the height of the door is one foot more than twice its width, and the height of the door is 7 feet.
Twice the width is 6 feet, and one foot more than that is 7 feet. Our answer checks out.
The width of the door is 3 feet.
Hope this helps!
