Notation

Question 1

ℤ

Answer 1

Integer

Question 2

ℕ

Answer 2

Natural number

Question 3

ℚ

Answer 3

Rational number

Question 4

∈

Answer 4

Element of

Question 5

∉

Answer 5

Not an element of

Question 6

⊂

Answer 6

Subset

Question 7

∪

Answer 7

Union

Question 8

ℝ

Answer 8

Real number

Question 9

I

Answer 9

Irrational

Question 10

(a,b)

Answer 10

{x: a<x<b}

Question 11

[a,b]

Answer 11

{x: a≤x≤b}

Question 12

(a+b)²

Answer 12

= a²+2ab+b²

Question 13

a³+b³

Answer 13

= (a+b)(a²-2ab+b²)

Question 13

Pascals triangle

Answer 13

(0) 1
(1) 1 1
(2) 1 2 1
(3) 1 3 3 2
(4) 1 4 6 4 1
(5) 1 5 10 10 5 1