What is the a aba abcba abcdcba thing called? ? in other words, 1 3 7 15 31 pattern?

How do you answer this question? (step by step)

The quadratic function h(t) = -16.1t^2 + 150 models a balls height, in feet, over time, in seconds, after its dropped from a 15 story building. from what height in feet was the ball dropped?

What can each term of the equation be multiplied by to eliminate the fractions before solving? x – + 2x = + x 2 6 10 12