First you want to use the distributive property. So, [tex]9*p-(9*4)=-18[/tex]. Which equals [tex]9p-36=-18[/tex]. Next use the addition property of equality to make your first step to isolate variable p. Which equals [tex]9p-36+36=-18+36[/tex]. Then simplify the equation down to [tex]9p=18[/tex]. Lastly, is the division property of equality [tex](9p)/9=18/9[/tex]. Once again simplify to [tex]p=2[/tex]. Always make sure to pull your answer back into the original equation to see if the answer is correct.
[tex]9(2-4)=-18[/tex]
[tex]9(-2)=-18[/tex]
[tex]-18=-18[/tex]
