Which expression represents the difference between 18 and an unknown number a. 18 - n b. 18 + n c. 18 divided by n d. 18 • n

Ithink i know it but i want to be sure so can you me out ?

You use technology ans find a sum of 6.712e-8. write this sum in standard form

The slope of cd is which segments are perpendicular to cd ? select each correct answer. gf , where g is at (6, 5)and fis at (10, 2) ef, where e is at (4, 1) and f is at (7,5) lm , where lis at (-2, 3) and m is at (-10, 9) jk , where jis at (1, -2) and k is at (10, – 14) next