Help? Look at the table of values below.

a | b
------
2 8
4 14
6 20

Which equation is represented by the table?

A. b = a + 14/2
B. b = 3a + 2
C. b = 4a - 4
D. b = 4a - 2

Question

Help? Look at the table of values below.  

a   |  b
------
2	8
4	14
6	20

Which equation is represented by the table?

A. b  =   a  +  14/2
B.  b  =  3a  +  2
C. b  =  4a  -  4
D. b  =  4a  -  2

e.mccormick · Answer

One of the easiest ways to solve this type is to plug in values and see results.  So if you look at the table and the equations, you have b=?  Where ? involves a.  So put in one of the a values and see if it works.  If it does not, you can cross it off.  If it does, try another a.  If all work, that is the answer.

anonymous · Answer

Ok, I'll do that!

anonymous · Answer

@e.mccormick is it c?

e.mccormick · Answer

Lets see. 2*4=8, 8-4=4... but for a=2, b=8.  Nope.

anonymous · Answer

Ohhh! D then, right?

e.mccormick · Answer

So c is out.  Ah, lets see.  I did not do all of the,.  Hehe. No, it also has problems.  And A has +14/2, which means 7 an odd number, and all these are even.  I think you found it by elimination!  But the goal is to test and eliminate rather than to guess and eliminate.

anonymous · Answer

oi how can it not be D? I don't understand? :(

e.mccormick · Answer

b = 4a - 2
Start with a=2.

4(2)-2=8-2=6.  On the chart, it is supposed to be 8 but we got 6.

anonymous · Answer

Ah I've got it! Massive thank you!

e.mccormick · Answer

np.  Now you get how plugging it in and trying it works.  This tactick, while sometimes slow, can solve a large number of questions.