# Math Help - find rule???

1. ## find rule???

find rule for linear function f(5)=-7 and f(-5)=10

2. ## Re: find rule???

Originally Posted by sluggerbroth
find rule for linear function f(5)=-7 and f(-5)=10
Since it's linear it's of the form \displaystyle \begin{align*} f(x) = m\,x + c \end{align*}.

You can substitute the two given points to get two equations in two unknowns to solve simultaneously

3. ## Re: find rule???

Originally Posted by sluggerbroth
find rule for linear function f(5)=-7 and f(-5)=10
$m = \frac{f(5) - f(-5)}{5 - (-5)}$

sub in the value for m in the point-slope form of a linear equation ...

$y - (-7) = m(x - 5)$