SOLUTION: The value in the table are generated by a rule of the form a = bc + d where b and d are constant. Find a when c = 19. c --->1 2 3 . . .19 a ---> 8 11 14 . . . Any help you can p

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Question 135060: The value in the table are generated by a rule of the form a = bc + d where b and d are constant. Find a when c = 19.
c --->1 2 3 . . .19
a ---> 8 11 14 . . .
Any help you can provide would be great. Thanks.
Answer by vleith(2983) (Show Source):
You can put this solution on YOUR website!
There a several ways to do this one. The form "" a = bc + d where b and d are constant" is just a line (the familiar y = mx + b). So you could figure out a slope and then do some math to get to the intercept.
But let's look at this as a logic problem and find some patterns.
Every increase of 'c' by 1, results in an increase of 'a' by 3. You can see that by finding the difference between each successive value in the series of 'c' and 'a' numbers.
So that means .
Now instead of moving up the 'a' and 'c' series, move back one. Decrease 'c' by 1 (1-1) and get 0. Decrease 'a' by 3 (8-3) and get 5. So when c = 0, a = 5.
=
Which means
Now plug in b and d

What is 'a' when 'c' = 19? I leave that to you :-D