10
,
−
5
,
−
14
3
,
9
,
3.77
,
−
1
3
π
,
9
,
−
3.8
,
23
The natural numbers are:
10
,
9
,
9
,
23
The whole numbers are:
10
,
9
,
9
,
23
The integers are:
10
,
−
5
,
9
,
9
,
23
The rational numbers are:
10
,
−
5
,
−
14
3
,
9
,
3.77
,
9
,
−
3.8
,
23
The irrational number is:
−
1
3
π
Find total number of integers.

Find how many integers is divisible by 2.

Eliminate even numbers.
11, 13, 15,..., 57, 59
This array contains 51 - 26 = 25 numbers.
Eliminate numbers before the first number divisible by 3 and after the last number divisible by 3.
15, 17, 19,..., 55, 57
This array contains 25 - 3 = 22 numbers.
Now we should eliminate numbers divisible by 3: 15, 21, 27...

There are 8 such numbers.
Therefore, there are 25 - 8 = 17 numbers that <span>can be evenly divided by neither 2 nor 3</span>
Make them both equal to y
y=-2x+6
2y=x+6 y=1/2x+3
These are perpendicular since ones slope is -2 and the other is the opposite, 1/2.