SOLUTION: If f(4)=0 and f(6)=6. Which of the following couldd represent f(x)? Answer is 2/3x-4. How?

Algebra ->  Functions -> SOLUTION: If f(4)=0 and f(6)=6. Which of the following couldd represent f(x)? Answer is 2/3x-4. How?      Log On


   

Question 936847: If f(4)=0 and f(6)=6. Which of the following couldd represent f(x)? Answer is 2/3x-4. How?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The line has the form,y=mx%2Bb
Use the two points to find m and b.
0=m%284%29%2Bb
4m%2Bb=0
.
.
6=m%286%29%2Bb
6m%2Bb=6
Subtract the first equation from the second to eliminate b.
6m%2Bb-4m-b=6-0
2m=6
m=3
Then use either equation to solve for b.
4%283%29%2Bb=0
12%2Bb=0
b=-12
.
.
.
highlight%28y=3x-12%29
Checking the solution,
3%284%29-12=0
3%286%29-12=6
Both points have been verified.
y=%282%2F3%29x-4 is not the correct solution to this problem.