[tex]f(x)=mx+b\to y=mx+b[/tex]
We have two points:
[tex](-3,\ 0);\ (-4,\ 7)[/tex]
The point slope form of the line:
[tex]y-y_1=m(x-x_1)\\\\m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
Substitute
[tex]m=\dfrac{7-0}{-4-(-3)}=\dfrac{7}{-1}=-7[/tex]
[tex]y-0=-7(x-(-3))\\\\y=-7(x+3)\\\\y=-7x-21[/tex]
Answer:
[tex]f(x)=-7x-21[/tex]
