Question

idk how to do this..
write the set in set -builder notation.
the set of all even integers greater than 20.
a.{x|x is a multiple of 10}
b.{x|x is even}
c.{x|x<0}
d.{x|x is an even integer and x >20}
someone please explain D:

Answer 1

hi. are you still stuck on this problem?

Answer 2

yes.

Answer 3

ok. well, let's read what the first option says.

Answer 4

ok

Answer 5

a says the set of all x such that x is a multiple of 10. this set would look like {10,20,30,40,....,100,...}

Answer 6

well, you get the picture. the member of the first set include all multiples of 10, but not all of the even numbers. also, the set you want has numbers >20 and 10 does not fall into that. so a. is out

Answer 7

tell me why b. does not fit into the set we want either

Answer 8

read the terms in the set builder notation in b.

Answer 9

start off with the set of all x. the line in the middle means such that and then there is the condition

Answer 10

ok hold on

Answer 11

i thought i was because its even

Answer 12

well, the above set contain even integers. however, b. contains all even integers, not just the ones bigger than 20

Answer 13

ohhh ok

Answer 14

we want a set that has all numbers bigger than 20 and are even, like 22, 24, etc

Answer 15

now what about c.?

Answer 16

oh ok so its D

Answer 17

because it says x is gretaer than 20

Answer 18

perfect. and they are even numbers

Answer 19

greater than 20

Answer 20

you did nicely yessi, is there anything else i can help you with?

Answer 21

thanks(:

Answer 22

if there is nothing else, i hope you have a lovely evening. take care

Answer 23

the medal was sweet... bye