Answer:
f(x) = -
x -

Explanation:
the equation of a line in slope- intercept form is
f(x) = mx + c ( m is the slope and c the y- intercept )
given f(- 5) = 2, that is when x = - 5 , y = 2
f(7) = - 4, that is x = 7, y = - 4
the 2points (- 5, 2 ) and (7, - 4 ) lie on the line
calculate m using the slope formula
m =

with (x₁, y₁ ) = (- 5, 2 ) and (x₂, y₂ ) = (7, - 4 )
m =
=
=
= -
, then
f(x) = -
x + c ← is the partial equation of the line
to find c substitute either of the 2 points into the partial equation
using (- 5, 2 ) , then
2 = -
(- 5) + c =
+ c ( subtract
from both sides )
-
= c
f(x) = -
x -
← equation of line