Question 430055
In words:
Cost = ( cost of 1 ticket minus [$3 x (extra tickets)] x total number of tickets
{{{ C = (90 - 3*(x-1))*x }}}
{{{ C = (90 - 3x + 3)*x }}}
{{{ C = 90x - 3x^2 + 3x }}}
{{{ C = -3x^2 + 93x }}}
check answer:
For 2 tickets:
{{{ C = -3*4 + 93*2 }}}
{{{ C = -12 + 186 }}}
{{{ C = 174 }}}
OK
Notice that for 30 tickets, The total cost is only $90