Yup, that's pretty easy.
You might like to leave the first row at the top for headers so you can
explain what's in the table below, but I'll get to that in a second.
In the first column, from row 2 onwards, put in the values of x, e.g. cell
a2 contains "1", cell a3 contains "2".
(If you want to be really whizzy, use autofill. Highlight the 1 and the 2,
put the cursor to the bottom right of the lower cell until it turns to a dark
cross and drag it down as far as you need, the values in the cells you drag
over should then be 3, 4, 5 etc).
In the second column insert the formulas that you want to use, so in cell
B2, if you're investigating "19+15x" insert the following in cell B2 and
press return:
=19+(15*a2)
For the heading to column B insert "19+15x" in cell B1. That doesn't start
with = so it will just display like that.
You can use autofill again to drag downwards.
(You could also do a single line where you see one instance at a time but
you said you wanted to compare, so I won't go into that one.)
Alternatively, read the help file to see what Excel says about entering
formulas.
