Question 495115
2.   Determine whether the relation {(–2, 3), (–5, 6), (3, 0), (1, 1)} is a function
<pre>
We look at the first coordinates -2, -5, 3, and 1. None of those are
the same, so it is function.
</pre>
3.   Delete one ordered pair so that the relation {(–4, 2), (1, 6), (0, 0), (–4, 6)} is a function.
<pre>
We look at the first coordinates -4, 1, 0, and -4. Two of those are
the same -4, so it is NOT a function.  To make it into a function we can
delete either (-4, 2) or (-4, 6).  You can put either of these as the
solution:

{(1, 6), (0, 0), (–4, 6)} or {(–4, 2), (1, 6), (0, 0)}



</pre>
Find ƒ(–5) for each function.

5.   ƒ(x) = 5x + 35  
<pre>
Everywhere you see an x, replace it by (-5)

     ƒ(-5) = 5(-5) + 35

Then simplify the right side:

     ƒ(-5) = -25 + 35

     ƒ(-5) = 10

</pre>
6.   ƒ(x) = x² – x  
<pre>
Everywhere you see an x, replace it by (-5)

     ƒ(-5) = (-5)² - (-5)

Then simplify the right side:

     ƒ(-5) = 25 + 5

     ƒ(-5) = 30
 
Edwin</pre>