Question 1156064
Let {{{ x }}} = the number of rows
{{{ ( x + 12 )*x = 1728 }}}
{{{ x^2 + 12x = 1728 }}}
I'll complete the square
{{{ x^2 + 12x + ( 12/2 )^2 = 1728 + ( 12/2 )^2 }}}
{{{ x^2 + 12x + 36 = 1764 }}}
{{{ ( x + 6 )^2 = 42^2 }}}
{{{ x + 6 = 42 }}}
{{{ x = 36 }}}
and
{{{ x + 12 = 48 }}}
there are 48 seats in each row
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check:
{{{ ( x + 12 )*x = 1728 }}}
{{{ ( 36 + 12 )*36 = 1728 }}}
{{{ 48*36 = 1728 }}}
{{{ 1728 = 1728 }}}
OK