If you have two terms in a sequence, then a term decreased by the previous term=common difference
so
30 and 27
27 decreased by 30 is -3
the common differce is -3
Parallel means lines that never meet, and perpendicular are lines that meet at right angles.
4. 1/3 6.-0.9 or -9/10 8. 2 1/3 10. -3.45 12.4.54 or 4 27/50
Yea I wanna say you have the right answer