Question 945556
Plot pages on the vertical axis
Plot minutes on the horizontal axis
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You are given 2 points:
( 120, 9 )
( 200, 17 )
Let {{{ p }}} = number of pages
Let {{{ t }}} = number of minutes
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Use the general point-slope formula
{{{ ( p - 9 ) / ( t - 120 ) = ( 17 - 9 ) / ( 200 - 120 ) }}}
{{{  ( p - 9 ) / ( t - 120 ) = 8 / 80 }}}
{{{  ( p - 9 ) / ( t - 120 ) = 1/10 }}}
{{{ p - 9 = ( 1/10 )*( t - 120 ) }}}
{{{ 10p - 90 = t - 120 }}}
{{{ 10p = t - 30 }}}
{{{ p = ( 1/10 )*t - 3 }}}
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check:
does it go through ( 120,9 ) ?
{{{ 9 = ( 1/10 )*120 - 3 }}}
{{{ 12 = 12 }}}
OK
does it go through ( 200,17 ) ?
{{{ 17 = ( 1/10 )*200 - 3 }}}
{{{ 20 = 20 }}}
OK
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given:
{{{ t = 360 }}}
{{{ p = ( 1/10 )*t - 3 }}}
{{{ p = ( 1/10 )*360 - 3 }}}
{{{ p = 36 - 3 }}}
{{{ p = 33 }}}
She will write 33 pages