Question 1094142
Let {{{ t }}} = time in years, starting now at {{{ t=0 }}}
Plot {{{ t }}} on the horizontal
Plot {{{ f }}} on the vertical
You are given 2 points on a line,
( 0, 155800 )
( 10, 40300 )
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(a)
Use the general point-slope formula
{{{ ( f - 40300 ) / ( t - 10 ) = ( 155800 - 40300 ) / ( 0 - 10 ) }}}
{{{ ( f - 40300 ) / ( t - 10 ) = 115500 / (-10 ) }}}
{{{ ( f - 40300 ) / ( t - 10 ) = -11550 }}}
{{{ f - 40300 = -11550t + 115500 }}}
{{{ f = -11550t + 155800 }}}
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check:
does it go through ( 10, 40300 ) ?
{{{ 40300 = -11550*10 + 155800 }}}
{{{ 40300 = -115500 + 155800 }}}
{{{ 40300 = 40300 }}}
OK
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(b)
The domain is from ( 0, 155800 ) to ( t, 0 )
{{{ 0 = -11550t + 155800 }}}
{{{ 11550t = 155800 }}}
{{{ t = 13.49 }}} yrs
The domain is from 0 to 13.49
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(c)
Find ( 7, f )
{{{ f = -11550*7 + 155800 }}}
{{{ f = -80850 + 155800 }}}
{{{ f = 74950 }}}
It is worth $74,950 in 7 yrs
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check the math