Question 148035
The data given tells me two points on the linear relation
{{{P[1]}}}({{{0}}},{{{1300}}})
{{{P[2]}}}({{{6}}},{{{100}}})
This is with {{{B}}},the book value plotted on the y-axis
and {{{n}}}, the number of years on the x-axis
{{{P[1]}}} says that when it's {{{0}}} years old (brand new),
it's worth {{{1300}}} dollars
{{{P[2]}}} says that when it's {{{6}}} years old, it's worth
{{{100}}} dollars (scrap value)
The formula to use, in terms of B, and n is
{{{(1300 - B) / (0 - n) = (1300 - 100) / (0 - 6)}}}
{{{(1300 - B) / (-n) = 1200 / (-6)}}}
multiply both sides by {{{(-1)/-1}}}
{{{(B - 1300) / n = -1200 / 6}}}
multiply both sides by {{{6n}}}
{{{6B - 7800 = -1200n}}}
{{{B = -200n + 1300}}} answer
Try values of n = 1,2,3,4,5,6 to check this