They are dependent events, because the probability of the second event depends on the result of the first event
If you replace the marble before picking up the second marble, then the first event didn't affect the second result ant the events were independent.
Given that you did not replace the marble, the second pick up has different probailities depending on the first result.
It’s the first one........
So when you use an equation like this, you use the PS2 method. P means you find the product of the first and last numbers in the equation, so in your problem it would be -20. S means the number in front of the 2nd number, and in your problem it would be 1 because anything times 1 is itself. The 2 means that you need to find two numbers that multiply to your product: -20, and the sum which is 1. And the two numbers are -4 and 5. And since it’s equal to zero, it’s x=-5 and x=4. Your welcome