Linear functions
We can observe in the table that when x goes from 3 to 5, y decreases
How much does y decrease?
it goes from 5 to -3, then it decreases
-3 -5 = -8
then, if y starts with 5 when x = 3, then when x = 5 its value will be
5 - 8 = -3
when x = 5 it is -3, then when x = 7
-3 - 8 = -11
We can say that every time x increases 2 unities, y decreases 8
How many times y decreases when x increase 1 unity?
it should decrease
-8/2 = -4
Then we can have more information
If x = 3, then y = 5
if x = 4, then y = 5-4 = 1
if x = 5, then y = 1-4=-3
if x = 6, then y = -3 - 4 = -7
if x = 7, then y = -7 - 4 = -11
We want to know what is the value of y with the previous x values,
when x = 2, x =1 and x = 0
if x = 2. then y = 9, because 9 - 4 = 5
if x = 1, then y = 13, because 13 - 4 = 9
if x = 0, then y = 17, because 17 - 4 = 13
Answer, when x = 0, then y = 17