sara215 said:
ok I'm going to attempt to make the chart
X f(x)
0 a
1 24
2 b
The table above shows some values for the function f. If f is a linear function what is the value of a + b?
A. 24
B. 36
C. 48
D. 72
E. It cannot be determined from the information given.
If a function is linear, then (change in f(x)) / (change in x)
is constant between any two points on the graph of the function.
Look at your chart...when x = 0, f(x) = a
When x = 1, f(x) = 24.
Between those two points,
change in f(x) is 24 - a
change in x is 1 - 0, or 1
So, (change in f(x))/change in x = (24 - a) / 1
Now, when x = 2, f(x) = b.
Between the two points (1, 24) and (2, b), we can also find (change in f(x)) / change in x
at x = 1, f(x) = 24. At x = 2, f(x) = b. Change in f(x) = b - 24. And change in x = 2 - 1, or 1
(change in f(x)) / change in x = (b - 24) / 1
So....
(24 - a) / 1 = (b - 24) / 1
24 - a = b - 24
You should be able to get the value of "a + b" by manipulating that equation.
