Question 263588
Let the time in years after the equipment 
was bought = {{{t}}}, for example, {{{t = 1}}} 
would be {{{1}}} year after it was bought
Let {{{V}}} = the value of the equipment
at any point in time
When {{{t = 0}}},{{{V[0] = 25000}}}
When {{{t = 10}}},{{{V[10] = 2000}}}
The equation to use is
{{{(V - V[0])/(t- t[0]) = (V[10] - V[0])/(t[10] - t[0])}}}
{{{(V - 25000)/(t - 0) = (2000 - 25000)/(10 - 0)}}}
{{{(V - 25000)/t = -23000/10}}}
{{{V - 25000 = -2300t}}}
{{{V = -2300t + 25000}}} answer
I'll plot this (V is in thousands of dollars)
{{{ graph( 500, 600, -2, 12, -2, 30, -2.3x + 25) }}}