If a rock falls from a height of 40 meters on earth, the height h (in meters) after x seconds is approximately h(x) = 40 - 4.9 x^2 when does the rock strike the ground? in seconds?

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.

How to write four times a number, minus 6,is equal to theee times the number+8 as an equqtion

Maria found the least common multiple of 6 and 15. her work is shown below. multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, . . multiples of 15: 15, 30, 45, 60, . . the least common multiple is 60. what is maria's error?