Which one of the following letters would be considered formal?
a. a letter of application
b. a letter of invitation to an anniversary party
c. a personal letter to an old friend
d. a -you note to your grandmother

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?

Average acceleration: i have no idea how to do this.

Which of the binomials below is a factor of this exression? 16x^2+40xy+25y^2 a.4x-5y b. 2x-5y c.4x+5y d.2x+5y