Answer:
[tex]x=\frac{-t-r}{p}[/tex]
Step-by-step explanation:
[tex]-t=r+px[/tex]
Switch sides:
[tex]r+px=-t[/tex]
Subtract r from both sides:
[tex]r+px-r=-t-r[/tex]
[tex]px=-t-r[/tex]
Divide both sides by p:
[tex]\frac{px}{p}=-\frac{t-r}{p}[/tex]
