accountant has been using straight$-$line depreciation on the equipment.

$($a$)$ How much was the annual depreciation for the original equipment $($in $ $)?$

$

$($b$)$ If the hydraulic lift had originally cost $$10,650,$ what would its residual value $($in $ $)$ be after $20$ years?

$ $$,x$

$($d$)$ What was the book value of the equipment inventory at the six$-$year point, substituting the new hydraulic lift for the original after the new lift had joined the inventory $($in $ $)?$ Enter a number.