Question 152238
b=h+7
bh/2=39 yhen bh=78
then

(h+7)h=78

h^2+7h-78=0



{{{h = (-7 +- sqrt( 7^2-4*1*78 ))/2 }}} =
{{{(-7 +- sqrt(361))/2 }}}={{{(-7 +- 19)/2 }}}
then h=(-7+19)/2=6
Answer:
h=6 and b=13