Asap and show steps solve this system of equations: x-y=12 x+y=20

Using inductive reasoning, what is the next two numbers in this set? 1,-7,13,-19 i got the numbers 14,-26 is that right?

As a self-employed seamstress, you know that it takes 7 yards of material to make 3 jackets. you bought 15 yards of material to make 7 jackets. did you buy enough material? if not, how much were you over or under?

Emmanuel added 888 links per minute to his chain mail. allesia started 202020 minutes after emmanuel and added 131313 links per minute to her chain mail. how long had emmanuel worked when allesia caught up to him, and how many links had he added?