2/5
Since 12 out of 30 marbles were black, you can assume that the percentage of black marbles in the bag is 40% (Ex: 12/30=.4) The probability that the marble you pick is black is equal to the percentage of black marbles in the bag. 40% is equal to 2/5.
Answer:
7x
Step-by-step explanation:
It equals 28 just like the problem with parentheses, 7x .
Answer: I doubt your in it anymore
Step-by-step explanation: