What is the greatest common factor of 84 and 210

The sat and act tests use very different grading scales. the sat math scores follow a normal distribution with mean 518 and standard deviation of 118. the act math scores follow a normal distribution with mean 20.7 and standard deviation of 5. suppose regan scores a 754 on the math portion of the sat. how much would her sister veronica need to score on the math portion of the act to meet or beat regan's score?

Define the type of sequence below. 7, 14, 28, 56, 112, a. neither arithmetic nor geometric b. arithmetic c. both arithmetic and geometric d. geometric

Triangles abd and ace are similar right triangles. witch ratio best explains why the slope of ab is the same as the slope of ac?