Question 882673
{{{V=S+12}}}
{{{V-4=4(S-4)}}}
Substitute eq. 1 into eq. 2,
{{{S+12-4=4S-16}}}
{{{-3S=-24}}}
{{{S=8}}}
.
.
.
{{{V=8+12}}}
{{{V=20}}}