What is the value of x?

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Three coins are flipped. what is the probability that there will be at least two tails?

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

Find the zeros of each function. f(x) = 6x^2 - 7x - 20