Question 964049
The Linear equation for a company that sells plastic airtight containers is
 P= a+bx, where
 P is the profit in Rands,
 x is the number of units sold, 
 and a and b are constants.
:
 When 100 units are sold, the profit is R21 000
a + 100b = 21000
 and when 450 units are sold, the profit is R126 000.
a + 450b = 126000
:
Determine the values if a and b.
Subtract the 1st equation from the 2nd equation
a + 450b = 126000
a + 100b = 21000
------------------Eliminates a, find b
0 + 350b = 105000
b = 105000/350
b = 300
Find a using the 1st equation
a + 100(300) = 21000
a + 30000 = 21000
a = 21000 - 30000
a = -9000
:
The equation P = 300x - 9000
Draw a neat graph showing profit as a function of the number of units sold.
{{{ graph( 300, 200, -200, 1000, -50000, 300000, 300x-9000) }}}