Question 1101041
You didn't ask any question. Usually
the question is: " At what value of {{{ m }}}
are the costs of A and B equal?
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Plan A:
(1) {{{ f(m) = .2m + 75 }}}
Plan B:
(2) {{{ f(m) = .35m }}}
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Set (1) = (2) 
{{{ .2m + 75 = .35m }}}
{{{ .15m = 75 }}}
{{{ m = 500 }}}
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After driving 500 miles, the costs of
the 2 plans are the same
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check:
(2) {{{ f(500) = .35*500 }}}
(2) {{{ f(500) = 175 }}}
and
(1) {{{ f(500) = .2*500 + 75 }}}
(1) {{{ f(500) = 100 + 75 }}}
(1) {{{ f(500) = 175 }}}
OK