
Patrick B. answered 07/24/19
Math and computer tutor/teacher
R-c > 0
400 + 25x - x^2 - 50 - 50x > 0
350 -25x - x^2 > 0
x^2 + 25x - 350 < 0
( x + 35 )( x - 10 ) < 0
x+35 ---> -35 is a zero
x-10 ---> 10 is a zero
for x<-35 the inequality is positive , so no, not in the solution
-35 < x < 10, the inequality is negative, so yes, is part of the solution
x>10, the inequality is positive so no, not in the solution.
the solution is 0 < x < 10
Note that when x=10, the revenue is 400 + 250 - 100 = 550 and so is the cost 550 = 50 +500
1 unit will return a profit of 424 - 100 = 324