Question 981449
b, base of the parallelogram
h, height of the parallelogram


{{{system(b*h=123,(b-4)*h=123-32)}}}


You can solve for both variables.



-
Start of the process:
{{{bh-4h=91}}}
and because you already know bh,
{{{123-4h=91}}}
{{{123-91=4h}}}
{{{4h=32}}}
{{{h=8}}}
-
{{{bh=123}}}
{{{b=123/h}}}