its not me..thats how you solved it in previous steps....this one m talking to (a) Find the marginal CDFs of X and Y: Marginal CDF of X (F_X(x)): To find the marginal CDF of X, we integrate the joint CDF over all possible values of Y. This operation isolates the marginal distribution of X. Let's calculate it step by step: F_X(x) = from 0 to of F(x, y) dy = from 0 to of (1 - e^(-x))(1 - e^(-y)) dy = (1 - e^(-x)) * [ from 0 to of (1 - e^(-y)) dy] = (1 - e^(-x)) * [y - (1/)e^(-y)] from 0 to = (1 - e^(-x)) * [ - 0 - (1/)(0 - 1)] = (1 - e^(-x))