The answer is (4x-5)(5x^2+1)
8 seconds
The hardest part of this is setting up the equation -- the calculations are pretty easy.
You're told that the time (needed to go from 0 to 100 MPH) is inversely proportional to the horsepower: what this means is that as horsepower gets larger, time gets smaller. This makes sense since the more horsepower you have, the less time it will take you to get to 100 MPH
You can think of this as:
200 HP = 10 seconds
250 HP = x seconds
You set the equation up as:
250 HP / 200 HP = 10 sec / x sec
Now, just cross multiply and solve:
250 / 200 = 10 / x
250x = (200 x 10)
250x = 2000
x = 2000 / 250
x = 8
So, as you increase the horsepower from 200 to 250, the time decreases from 10 seconds to 8 seconds.
Hope this helps!
Good luck.
We actually don't need to do any computation. By definition, the inverse function 
changes the role of input and output. So, if a function f maps x onto y, the inverse function maps y onto x.
You have to think like this: if the function makes a step further, the inverse function makes that same step back.
This means that the composition 
is always the identity function 
. In fact,
So, for every function, you have
<span>y=34x−52
34x - y - 52 = 0</span>
5x + 60y = 35
x +y = 1.5 : rewrite as x = 1.5-y and substitute this formula for x in the first one:
5(1.5-y) + 60y = 35
distribute:
7.5 - 5y + 60y = 35
combine like terms:
7.5 + 55y = 35
subtract 7.5 from both sides:
55y = 27.5
divide both sides by 55 to solve for y
y = 27.5 / 55 = 0.5
now substiute 0.5 for y in the 2nd equation:
x + 0.5 = 1.5
x = 1.5 - 0.5 = 1
he walked for 1 hour
