Given

we have

Squaring both sides, we have

And finally

Note that, when we square both sides, we have to assume that

because we're assuming that this fraction equals a square root, which is positive.
So, if that fraction is positive you'll actually have roots: choose

and you'll have

Which is a valid solution. If, instead, the fraction is negative, you'll have extraneous roots: choose

and you'll have

Squaring both sides (and here's the mistake!!) you'd have

which is not a solution for the equation, if we plug it in we have

Which is clearly false
Using the rational root theorem, it is found that your friend is correct.
<h3>What is the rational root theorem?</h3>
- It is a theorem that states that for a polynomial with integer coefficients, with q being the factors of the leading coefficient and p being the factors of the constant, every <u>possible rational root</u> is the format
.
In this problem:
- The leading coefficient is 1, hence it's only factor is
, thus guaranteeing that every possible rational zero is an integer, which means that your friend is correct.
To learn more about the rational root theorem, you can take a look at brainly.com/question/10937559
Try this solution:
1. according to the condition

2. for more details see the attached graph.
Answer: [0;+oo)
I don't think it is linear b/c i don't think you can plug in the numbers and get it to work. This may not be right though b/c I did this in my head.
Answer:
i dont know
Step-by-step explanation:
it would solve for x though
then divide x by the number after the equal sighn then thayts your answer