Question 391268
Let {{{c}}} = costs
Let {{{b}}} = number of books sold
given:
{{{c = 4b + 3500}}}
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{{{15b > 4b + 3500}}}
{{{11b > 3500}}}
{{{b > 318}}}
You must sell 319 books
check answer:
{{{15b > 4b + 3500}}}
{{{15*319 > 4*319 + 3500}}}
{{{4785 > 1276 + 3500}}}
{{{4785 > 4776}}}
OK
and with {{{b = 318}}}
{{{15*318 > 4*318 + 3500}}}
{{{4770 > 1272 + 3500}}}
{{{4770 > 4772}}} -not true
So, 318 is too small