Question 416309
(1) {{{P = V - 4}}}
(2) {{{V + P = 10}}}
Substitute (1) into (2)
(2) {{{V + V - 4 = 10}}}
{{{2V = 14}}}
{{{V = 7}}}
and, since
{{{P = V - 4}}}
{{{P = 7 - 4}}}
{{{P = 3}}}