Incorrect. Your first step was a good one, because multiplying both sides by 3 gives you $\displaystyle{p}-{15}={30}\usepackage{cmbright}\Huge\$ . However, adding 5 to both sides yields $\displaystyle{p}-{10}={25}\usepackage{cmbright}\Huge\$ and does not isolate the variable. You probably forgot to multiply the 5 by 3 when you multiplied $\displaystyle\frac{{1}}{{3}}{p}\usepackage{cmbright}\Huge\$ by 3. The correct method is to add 5 to both sides first, and then multiply both sides by 3.