Producers will make 1000 refrigerators available when the unit price is $280.00. at a unit price of $400, 5000 refrigerators will be marketed . find the equation relating the unit price p of a refrigerator to the quantity supplied x if the equation is known to be linear.
p =
how many refrigerators will be marketed when the unit price is $ refrigerators
what is the lowest price at which a refrigerator will be marketed? $ (lowest price)

For linear equations we use:

p=mx+b   ------  (1)

Now we have the following coordinates:

(x1,p1)= (1000,280) and (x2, p2)=(5000,400)

First we need slope (m)

m=

=

Now we will plug the value of m in the first equation

=>

=> b = 250

Now plug into p=mx+b using only m=0.03 and b=250

When the unit price is $440, we can plug in 440 in for p;

=>

=>

=> x = 6333 refrigerators

The lowest price at which  a refrigerator will be marketed, we can find this by plugging x = 0 in p=mx+b.

=> p = $250

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value