To add or subtract rational expressions with unlike denominators, first find the LCM of the denominator. The LCM of the denominators of fraction or rational expressions is also called least common denominator, or LCD. Write each expression using the LCD.
23064908
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I am not sure
but 90 per cent its option b
From calculus, to determine the maxima or minima of the graph, get the derivative of the equation and equate to zero. So, we derive first the equation of the graph and equate to zero.
C = 0.25x² - 80x + 30000
dC/dx = 0 = 0.5x - 80 + 0
0.5x = 80
x = 80/0.5
x = 160 units
The minimum cost (although not asked) is:
C = 0.25(160)² - 80(160) + 30000
C = $23,600
The answer is 160 units.