Question 868023
{{{(1/2)*(2+b)*b=40}}}
{{{(2+b)*b=80}}}
{{{b^2+2b-80=0}}}
{{{(b+10)(b-8)=0}}}
Two solutions:
{{{b+10=0}}}
{{{b=-10}}}
and
{{{b-8=0}}}
{{{b=8}}}