Answer:
Step-by-step explanation:
Answer:
When we have a rational function like:

The domain will be the set of all real numbers, such that the denominator is different than zero.
So the first step is to find the values of x such that the denominator (x^2 + 3) is equal to zero.
Then we need to solve:
x^2 + 3 = 0
x^2 = -3
x = √(-3)
This is the square root of a negative number, then this is a complex number.
This means that there is no real number such that x^2 + 3 is equal to zero, then if x can only be a real number, we will never have the denominator equal to zero, so the domain will be the set of all real numbers.
D: x ∈ R.
b) we want to find two different numbers x such that:
r(x) = 1/4
Then we need to solve:

We can multiply both sides by (x^2 + 3)


Now we can multiply both sides by 4:


Now we only need to solve the quadratic equation:
x^2 + 3 - 4*x - 4 = 0
x^2 - 4*x - 1 = 0
We can use the Bhaskara's formula to solve this, remember that for an equation like:
a*x^2 + b*x + c = 0
the solutions are:

here we have:
a = 1
b = -4
c = -1
Then in this case the solutions are:

x = (4 + 4.47)/2 = 4.235
x = (4 - 4.47)/2 = -0.235
Answer:
108
Step-by-step explanation:
we first add 7+8=15 then 15×2=30 30+6=36 36×2=108
Distance = rate x time
D = 450 mph x 2.5 h
D = 1,125 miles
Answer:
Debbie runs 9 feet per second: 9 ft/s
Jessica runs 1 mile in 440 seconds: 414/50 ft/s = 207/25 ft/s = 8 7/25 ft/s
jesssica runs 131 feet in 10 seconds: since 1 mile = 5280 ft we have 1/470 mi/s = 5280/470 ft/s = 528/47 ft/s = 11 11/47 ft/s
ron runs 603 feet in 1 minute: 547 ft/min = 603/60 ft/s = 201/20 ft/s = 10 1/20 ft/s
Since:
11 11/47 > 10 1/20 > 9 > 8 7/25
Emily runs the fastest.