SOLUTION: Write an equation for the linear function f(x) that satisfies the condition f(2) = 8 and f(1) = 12. I can't remember how to do this.

Algebra ->  Linear-equations -> SOLUTION: Write an equation for the linear function f(x) that satisfies the condition f(2) = 8 and f(1) = 12. I can't remember how to do this.       Log On


   



Question 895677: Write an equation for the linear function f(x) that satisfies the condition f(2) = 8 and f(1) = 12.
I can't remember how to do this.

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The general form of a linear equation is f%28x%29=mx%2Bb
Substitute with the points you know.
f%282%29=8
1.8=2m%2Bb
f%281%29=12
2.12=m%2Bb
Now solve for m and b
Subtract eq. 2 from eq. 1
2m%2Bb-m-b=8-12
m=-4
Then use either equation to solve for b
12=-4%2Bb
b=16
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highlight%28f%28x%29=-4x%2B16%29