SOLUTION: Find a linear function f such that f(3)=9 and f(7)=17. Then find f(-3).

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Question 1086060: Find a linear function f such that f(3)=9 and f(7)=17. Then find f(-3).
Found 2 solutions by ikleyn, MathTherapy:
Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
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f(x) = 9+%2B+%28%28f%287%29-f%283%29%29%2F%287-3%29%29%2Ax = 9+%2B+%28%2817-9%29%2F4%29%2Ax = 9 + 2x.


f(-3) = 9 + 2*(-3) = 9 - 6 = 3.

Solved.



Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Find a linear function f such that f(3)=9 and f(7)=17. Then find f(-3).
Linear function: matrix%281%2C3%2C+f%28x%29%2C+%22=%22%2C+2x+%2B+3%29

For f(- 3), substitute - 3 for x in the linear function, and simplify.