Question 1140263
Let {{{ C }}} = the cost of a plan
Let {{{ n }}} = number of months belonging to a plan
(1) {{{ C = 25 + 87n }}}
(2) {{{ C = 100 + 72n }}}
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(2) starts out costing more. Set (1) equal to (2)
to find the point where (1) starts costing more.
{{{ 25 + 87n = 100 + 72n }}}
{{{ 15n = 75 }}}
{{{ n = 5 }}}
After 5 months, (1) will start costing more
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check:
{{{ 25 + 87*5 = 100 + 72*5 }}}
{{{ 25 + 435 = 100 + 360 }}}
{{{ 460 = 460 }}}
OK