(7+x)+x=15
I did trial and error to get x=4.
It looks like you have the domain confused for the range! You can think of the domain as the set of all "inputs" for a function (all of the x values which are allowed). In the given function, we have no explicit restrictions on the domain, and no situations like division by 0 or taking the square root of a negative number that would otherwise put limits on it, so our domain would simply be the set of all real numbers, R. Inequality notation doesn't really use ∞, so you could just put an R to represent the set. In set notation, we'd write

and in interval notation,

The <em>range</em>, on the other hand, is the set of all possible <em>outputs</em> of a function - here, it's the set of all values f(x) can be. In the case of quadratic equations (equations with an x² term), there will always be some minimum or maximum value limiting the range. Here, we see on the graph that the maximum value for f(x) is 3. The range of the function then includes all values less than or equal to 3. As in inequality, we can say that
,
in set notation:

(this just means "f(x) is a real number less than or equal to 3")
and in interval notation:
![(-\infty,3]](https://tex.z-dn.net/?f=%20%28-%5Cinfty%2C3%5D%20)
If you have edunuity, the answer is... Two parallel lines will have the same slope. The slopes of parallel lines have to be equal. The y-intercepts of those two lines have to be different, otherwise they would be the same line. The x-intercepts of the parallel lines would also be different.
So, it depends. Imma give you two answers, all of which are the same at the end. They just have different ways to do it.
1. So, it's<span> $9 per hour, or $9 per 60 min </span>
<span>You can write a ratio: 9/60 = n/1 </span>
<span>In this case you have to divide 9 by 60 cause
60/60 = 1 </span>
<span>And n=0.15 </span>
<span>Answer: you earn 15 cents per min.
2.</span><span>$9 = 900 cents </span>
<span>900 cents divided by 60 minutes = 15 cents in a minute.
Hope this helps love!! :)</span>