X + (x + 2) + ( x + 4) + (x + 6)
----------------------------------- = 15
4
4x + 12
--------- = 15
4
Multiply by 4 on both sides
4x + 12 = 60
subtract 12 from both sides
4x = 48
divide by 4 on each side
x = 12
x + 2 = 14
x + 4 = 16
x + 6 = 18
x+2 > 10 solves to x > 8 after we subtract 2 from both sides
So set A is the set of real numbers that are larger than 8. The value 8 itself is not in set A. The same can be said about 5 as well.
Set B is the set of values that are larger than 5 since 2x > 10 turns into x > 5 after dividing both sides by 2. The value x = 5 is not in set B since x > 5 would turn into 5 > 5 which is false. The values x = 6, x = 8, and x = 9 are in set B.
----------------
Summarizing everything, we can say...
5 is not in set A. True
5 is in set B. False
6 is in set A. False
6 is not in set B. False
8 is not in set A. True
8 is in set B. True
9 is in set A. True
9 is not in set B. False
28: 1, 2, 4, 7, 14, 28
40: 1, 2, 4, 5, 8, 10, 20, 40
The common factors are 1, 2, and 4.
You can use a factor rainbow to help you find the factors (:
notice above, all we did, was isolate the "recurring part" to the right of the decimal point, so the repeating 09, ended up on the right of it.
now, let's say, "x" is a variable whose value is the recurring part, therefore then
now, the idea behind the recurring part is that, we then, once we have it all to the right of the dot, we multiply it by some power of 10, so that it moves it "once" to the left of it, well, the recurring part is 09, is two digits, so let's multiply it by 100 then,
and you can check that in your calculator.
