This is a basic algebra question, I could use a little assistant with I just want guidance with symbolic rule.
A photocopier was bought for 4000 dollars and depreciates at a rate of $500 per year.
Determine a symbolic rule for the value of the copier.
Here's what I have thought: $c$ represents the cost of the printer, $x$ represents the year.
$C=4000(x)-500$
Could this be a symbolic rule?
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$\begingroup$Since the depreciation rate is constant, I suppose you understand that, as function of time, the value of the copier is linear. This means that Cost = a + b t (t being in years). At time t=0, the value Cost is 4000 (you just bought it), then a = 4000. After the first year (t=1), the cost is 4000 - 500 = 3500. Then a + b = 3500, then b = -500. So the value is just 4000 - 500 t.
$\endgroup$ $\begingroup$If $x$ is the number of years from the purchase, the value should be $$C=max\{4000-500x,0\}$$ The $max$ function is needed because the value cannot be negative, even after a long time.
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