A ball fell for 20 seconds at a rate of 10 feet per second. A second ball fell for 2x less seconds at a rate of speed that is x feet per second slower than the first ball.

Which of the following equations could be used to determine how far the second ball fell?

A. y = (2x^2 - 40x + 200) ft

B. y = (2x^2 - 12x + 30) ft

C. y = (-2x^2 + 200) ft

D. y = (-2x^2 + 30) ft

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870

a mantle plume is an upwelling of abnormally hot rock within the earth's mantle. as the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcanic centers known as hotspots and probably also to have caused flood basalts.

step-by-step explanation:

i believe a. 12x≥120 is the answer