Question 1039486
(90+5x)(200-10x) = 17600
Therefore
-50x^2 +100x +1800 = 17600

We divide both sides by -50 

x^2 -2x -8 = 0 This is quadratic equation x = 4. This means that we have dropped the price four times. Which means 4 *10 = 40 Therefore the price = 200-40 = 160 and we have sold 4*5 + 90 jackets which is 110 
To see if we have done it correctly we multiply 110* 160 and we get 17600

We solve the second part of the problem the same way and we get x=8
This means we have dropped the price 8 times which is 8*10 = 80. This means the price has to be 200 - 80 = 120
and the number of jackets should be 90+ 8*5 = 130