Answer:
We have:
x < 4 AND x > a.
if a = 4 and we use an "or" instead of the "and" we have:
x < 4 or x > 4.
This is:
"x is larger than 4 or smaller than 4."
Then the solution of this is all the real numbers except the value x = 4.
The set of solutions can be written as:
{xI x ∈ R \ [4]}
Where this reads:
"x belongs to the set of the reals minus the number 4".
Or we also could write it as:
x ∈ (-∞, 4) ∪ (4, ∞)
Where we have two open ends in the "4" side, so the value x = 4 does not belong to that set.
let h = horse, let c = cow, let p = pig
so,
hcp
hpc
cph
chp
phc
pch
so, that is 6 different ways she can arrange it.
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.
