Robin currently has 50 subscribers on her You. Tube channel, and Dimitri currently has 17 subscribers. Robin gains 4 subscribers every week, while Dimitri gains 7 subscribers each week. Part A: Set up a system of equations to shows each person's subscribers.

Part B: After how many weeks will Robin and Dimitri have the same number of subscribers?

Part C: How many subscribers will Robin and Dimitri have when their subscriber count is equal?

Part A :

Robin : 50 divided by 4 = 12.5, Robin took 12.5 Weeks to get to 50 subscribers.

Dimitri : 17 divded by 7 = 2.4, Dimitri took 2.4 weeks to get to 7 subscribers.

Part B : In 7 weeks, Dimitri will have 66 subscribers, And in 4 weeks, Robin will have 66 subscribers. So after 7 weeks for Robin and 4 for Dimitri

Part C , They will have 66 subscribers. After 7 weeks Dimitri will have 66 subcribers, and after 4 weeks Robin will have 66 subscribers.

Explanation :

I have calculated out Robins and Dimitris subscribers counts with math.

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option