the linear function has the form:
y = mx + c
where m is the rate of change and c is constant
to find m and c, substitute with x and y from the table
if x = 6 , y = 4
so, 4 = 6m + c (1)
and if x = 8 , y = 0
so, 0 = 8m + c (2)
from (2)
c = -8m (3)
from (3) and at (1)
4 = 6m - 8m
so, 4 = -2m
m = 4/-2 = -2
c = -8 * -2 = 16
y = -2x + 16
now substitute with x = 7
y = -2 * 7 + 16 = -14 + 16 = 2 which agree with the value from the table
and when x = 9
y = -2 * 9 + 16 = -18 + 16 = -2 which agree with the value from the table
so, the function is linear
so, the last answer of the question, is the function non-linear?
C: No, because it has a constant rate of change.
the answer is option C