A bag contains red, black, white and brown balls. The probability of getting a red ball from a bag filled with balls is 2/13 and the number of black balls in the bag is 5. If the white ball is 30% less than the brown ball and 40% more than the black ball, find the number of red balls.

Step-by-step explanation:

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).