Answer:
[tex]f(x)=-1.5x-3.5[/tex]
Step-by-step explanation:
Let
x ----> the input value (independent variable)
y ----> the output variable (the dependent variable)
we have
f(-9)=10 and f(-1)=-2
so
we have the points
(-9,10) and (-1,-2)
step 1
Find the slope m
The formula to calculate the slope between two points is equal to
[tex]m=\frac{y2-y1}{x2-x1}[/tex]
substitute the values
[tex]m=\frac{-2-10}{-1+9}[/tex]
[tex]m=\frac{-12}{8}[/tex]
[tex]m=-1.5[/tex]
step 2
Find the equation of the line in slope point form
[tex]y-y1=m(x-x1)[/tex]
we have
[tex]m=-1.5[/tex]
[tex](x1,y1)=(-1,-2)[/tex]
substitute the values
[tex]y+2=-1.5(x+1)[/tex]
[tex]y+2=-1.5x-1.5[/tex]
[tex]y=-1.5x-1.5-2[/tex]
[tex]y=-1.5x-3.5[/tex]
Write in function notation
[tex]f(x)=-1.5x-3.5[/tex]