Answer:
Step-by-step explanation:
c(t)=40:0≤t≤400
=40+0.50 (t-400):t≥400
To find the surface area, multiply length x width x height.
let "length" = l
l x 32 x 36 = 4344
Simplify
l x (32 x 36) = 4344
l x 1152 = 4344
Isolate the length. Divide 1152 from both sides
(l x 1152)/1152 = (4344)/1152
l = 4344/1152
l = 3.77 (rounded)
3.77 cm is your length.
hope this helps
Answer:
10 hours
Step-by-step explanation:
(150/x) + 1.5 + (450/(x+15)) = 600/x
Multiply through by x(x + 15):
150(x + 15) + 1.5x(x + 15) + 450x = 600(x + 15)
150x + 2250 + 1.5x^2 + 22.5x + 450x = 600x + 9000
150x + 2250 + 1.5x^2 + 22.5x + 450x - 600x - 9000 = 0
1.5x^2 + 22.5x - 6750 = 0
x = (-22.5 +/- sqrt(22.5^2 - 4(1.5)(-6750))) / (2*1.5)
x = (-22.5 +/- sqrt(506.25 + 40500)) / 3
x = (-22.5 +/- sqrt(41006.25)) / 3
x = (-22.5 +/- 202.5) / 3
x = 180/3 or -225/3
x = 60 or -75
But a negative number doesn't make sense, so therefore x = 60, so the journey took 600/60 = 10 hours.
Q) Without a calculator, we must estimate the value of the following expression:
![3-\sqrt[]{38}.](https://tex.z-dn.net/?f=3-%5Csqrt%5B%5D%7B38%7D.)
A) I estimate 3 - √38 to be approximately -3.2.
First, we estimate the value of √38. √38 is between √36 and √49, but close to √36 (since 38 is closer to 4 than it is to 9). Since √36 is 6, √38 is probably something like 6.1 or 6.2. Filling 6.2 in the expression and simplifying, we have this:
So, I expect the number 3 - √38 to be close to -3.2.
Using a calculator we find that: 3 - √38 ≅ -3.16, which it is approximately the result that we found.
Answer
Without a calculator we find that 3 - √38 ≅ -3.2.
