Question 1059127
They are producing sofas at a certain rate,
and rate is the slope, {{{ m }}} in a linear equation
{{{ m = 245 }}} sofas/day
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{{{ 1235 }}} sofas is a constant number of sofas you
start off with, but if you want to begin at day one,
subtract out {{{ 245*3 = 735 }}} sofas
{{{ 1235 - 735 = 500 }}} is the constant term, {{{ b }}}
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Now let {{{ t }}} = time in days to make {{{ N }}} sofas
The equation would be:
{{{ N(t) = 245t + 500 }}}
You are given {{{ N(t) = 5400 }}}
{{{ 5400 = 245t + 500 }}}
{{{ 245t = 4900 }}} 
{{{ t = 20 }}}
20 days are needed to make 5400 sofas
( with the 3 days included, which I think they want )
Feel free to get another opinion, too