Answer:
Step-by-step explanation:
The first step is to take p on both sides:
[tex]A - p = p + p*r*t - p[/tex]
On the right hand side, cancel p and -p, since [tex]p-p=0[/tex]. The equation will be:
[tex]A - p = p*r*t[/tex]
Then, divide both sides of the equation by p*t:
[tex]\frac{A-p}{p*t} = \frac{p*r*t}{p*t}[/tex]
On the right hand side, p*t can be cancelled:
[tex]\frac{A-p}{p*t} = r[/tex]
