What is the sum of the first 20 terms in the arithmetic series?

−6+(−2)+2+6+

624

640

654

680

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?

Labc is reflected across x = 1 and y = -3. what are the coordinates of the reflection image of a after both reflections?

Julian wrote the following numeric pattern on the board3,10,17,24,31,38.what numbers of julian's pattern are compound numbers.