1-First let’s list the numbers between 210 to 220, except the even ones since they’re a multiple of 2:
211; 213; 215; 217; 219
Let’s remove 213, and 219 because they’re multiples of 3 (2+1+3=6; 2+1+9=12), 215 is multiple of 5, so let’s remove it.
That leave’s is with 211, and 217.
We can remove 217, because it’s a multiple of 7, leaving us with 211.
2- It’s deductive reasoning, because you started with a more general idea.
3- {-7, -6, -5, -4, -3, -2, -1, 0, 1}
4- {x e R, x>=-2}
5-{-1, 0, 1}
6- {x∣-4≤ x ≤6}
7- [-20, ♾ )
8- On a number line, make a circle around -1, and continue the line to minus infinity.
9- On a number line, make a circle on -3, and continue to minus infinity. Make a ring on 0, and continue to infinity.