input output

Question

write a rule(equation) that works for the input/output table  Find the missing output input

input   output

5         11

6         14

10        26

14        38

17           

            56

Answer 1

y = 3x - 4

 

Take the first two points:

 

(5,11) and (6,14)    Note that you could use any of them, but the numbers are smaller for these two.

 

Slope m = (14-11)/(6-5) = 3/1 = 3

 

Take either point and use the point-slope formula:

y - 11 = 3(x-5)

 

Distribute:

y - 11 = 3x - 15

 

Add 11 to both sides:

y = 3x - 15 + 11

 

Combine like terms:

Answer: y = 3x - 4

 

 

f(17) = 3(17) - 4 = 51-4 = 47

 

f^-1(56) =>  y=56=3x-4

56=3x-4

56+4 = 3x

60 = 3x

x = 20

 

Hope this helps.

Jason