<p>x f(x)
4 5
8 a
12 9</p>
<p>z g(z)
5 4
10 b
20 7
The table above shows values for the functions f and g. If f and g are linear functions what is the value of a - b?
A) 0 B) 1 C) 2 D) 3 E) 4</p>
<p>For a, I got a value of 7. The pattern seems to be you divide x by 2 and then add 3. For b, I got a value of 5, with a pattern of dividing x by 5 and then adding 3. I don’t know how to calculate those because I figured it out just by looking at the numbers. Sorry if this doesn’t help you out too much. (The answer is choice C, 2.)</p>
<p>Actually makes ample sense. I wonder why I couldnt figure it out. Thanks though.</p>
<p>You don’t really need to compute the actual linear function, just note that 8 is halfway between 4 and 12, so a is halfway between 5 and 9 (7). Also, 10 is 1/3 of the way between 5 and 20, so b is 1/3 of the way between 4 and 7 (5). 7-5 = 2. It’s a good strategy if you’re looking to save time.</p>