Test 7 Section 3 - #9 (page 771)

This one is just straight algebra.  As is often the case with the grid-in questions, we don't have the option of using plug-in or backsolve.

2(x - 3) = 8        (what we're given)

x - 3 = 4            (divide both sides by 2)

x = 7                 (add 3 to both sides)

Now we just need to put 7 in for x in the expression:

(x - 3)/(x + 3) 

(7 - 3)/(7 + 3)    (substitute 7 for x)

4/10

We can grid in our answer as 0.4, 4/10, 2/5, etc.  Me? I prefer to use decimals.