Let the amount that Yamini and Fatima contributed be x and y respectively towards the Prime Minister’s Relief fund.

Amount contributed by Yamini + Amount contributed by Fatima = 100

x + y = 100

It can be observed that (100, 0) and (0, 100) satisfy the above equation. Therefore, these are the solutions of the above equation. The graph is constructed as follows.

Here, it can be seen that variable x and y are representing the amount contributed by Yamini and Fatima respectively and these quantities cannot be negative. Hence, only those values of x and y which are lying in the 1^{st} quadrant will be considered.