It’s 42 heheeeee I’m Michel Jackson
Answer:
C. 1/(x^2 +1) > 0
Step-by-step explanation:
The cube of a negative number is negative, eliminating choices B and D for certain negative values of x.
1/x^2 is undefined for x=0, so cannot be compared to zero.
The value 1/(x^2+1) is positive everywhere, so that is the expression you're looking for.
1/(x^2 +1) > 0
Answer:
b.
Step-by-step explanation:
We have to look at sign changes in f(x) to determine the possible positive real roots.

There is only one sign change here, between the -8x and the +4. So that means there is only 1 possible real positive root.
Now we have to look at sign changes in f(-x) to determine the possible negative real roots.

There are 3 sign changes here. That means there are either 3 negative roots or 3-2 = 1 negative root. So we have:
1 positive
3 or 1 negative
We need to pair them up now with all the possible combinations.
If we have 1 positive and 1 negative, we have to have 2 imaginary
If we have 1 positive and 3 negative, we have to have 0 imaginary
Keep in mind that the total number or roots--positive, negative, imaginary--have to add up to equal the degree of the polynomial. This is a 4th degree polynomial, so we will have 4 roots.
Answer: Your brother is 15 years old right now.
Step-by-step explanation:
Let be "m" your currently age and "b" your brother's currently age.
Knowing that right now he is three times (this indicates multiplication) as old as you, you can write the following equation:

In five years your age will be:

And your brother's age will be:

Then, if in five years, your brother will be twice as old as you, you can set up the second equation:

Then, the System of equations is:

Apply the Substitution method and substitute the first equation into the second one and solve for "m":

Substitute the value of "m" into the first equation and evaluate in order to find "b":
