Question 274429
Let {{{b}}} = total number of bikes
given:
There are {{{60}}} new bikes ,so
used bikes  = {{{b - 60}}}
{{{b/4 = b - 60}}}
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Multiply both sides by {{{4}}}
{{{b = 4b - 240}}}
Subtract {{{b}}} from each side
{{{0 = 3b - 240}}}
Add {{{240}}} to both sides
{{{3b = 240}}}
{{{b = 80}}}
There are {{{b - 60 = 80 - 60}}}
{{{80 - 60 = 20}}} used bikes in stock