Given that the advertising company had a setup fee of $80, this would mean that
[tex]y=80[/tex]Next, since it is stated that they add $4 for every advertisment, we let x as the number of advertisement, and this would mean that we add 4x to the equation that we initially had
[tex]y=80+4x[/tex]Now, to write ordered pairs for the fees for 10, 20, 30, and 40 advertisements, we just have to substitute these values to the equation
x = 10
[tex]y=80+4x[/tex][tex]y=80+4(10)[/tex][tex]y=80+40[/tex][tex]y=120[/tex]( 10, 120 )
x = 20
[tex]y=80+4(20)[/tex][tex]y=80+80[/tex][tex]y=160[/tex]( 20, 160 )
x = 30
[tex]y=80+4(30)[/tex][tex]y=80+120[/tex]