x + y = 1

x – y = 1

xy = 1

$$\frac{x}{y}=1$$  

x + y = 2

x – y = 1 $$x-y=\frac{7}{2}$$  

xy = $$-\frac{33}{4}$$  

$$\frac{x}{y}=\frac{3}{11}$$  

n(AB) = 9

$$\left\{\left(1,a\right),\left(2,b\right)\right\}\subset A\times B$$  

  $$A\times B=B\times A$$         

$$n\left(A\times A\right)=n\left(B\times B\right)$$  

$$n\left(A\times B\right)=n\left(B\times A\right)$$  

$$\left(A\times B\right)\cap\left(B\times A\right)=\left\{\right\}$$  

$$\left\{\left(1,a\right),\left(a,a\right)\right\}\subset A\times B$$  

$$n\left(A\times A\right)=n\left(B\times B\right)$$  

$$n\left(A\times B\right)=5$$  

$$\left(A\times B\right)\cap\left(B\times A\right)=\left\{\right\}$$  

  $$n\left[\left(A\times B\right)\cup\left(B\times A\right)\right]<n\left[\left(A\times B\right)+\left(B\times A\right)\right]$$  

  $$\left(A\times B\right)=\left(B\times A\right)$$  

$$A\times B$$   = {(0, 1), (0, 3), (0, 5), (2, 1), (2, 3), (2, 5)}

$$B\times A$$  = {(1, 0), (1, 2), (3, 0), (3, 2), (5, 0), (5, 2)}

$$A\times A$$  = {(0, 0), (0, 2), (2, 0), (2, 2)}

$$B\times B$$  ={(1, 1), (1, 3), (1, 5), (3, 1), (3, 3), (3, 5)}

$$n\left(A\times B\right)=8$$  

$$n\left(B\times A\right)=8$$  

$$n\left(A\times A\right)=16$$  

$$n\left(B\times B\right)=8$$  

{(1, 2), (3, 1), (3, 4), (4, 2), (5, 3), (6, 5)}

{(1, 2), (2, 0), (3, 1), (3, 4), (4, 2), (5, 3), (6, 5)}

{(1, 2), (1, 3), (3, 1), (3, 4), (4, 2), (5, 3), (6, 5)}

{(2, 1), (0, 2), (1, 3), (4, 3), (2, 4), (3, 5), (5, 6)}

โดเมนของ r₁ = A

เรนจ์ของ r₂ = A

$$\left\{1\right\}\in A$$  

r₁ และ r₂ เป็นความสัมพันธ์ใน A

D_r = A

R_r  = A

n(r) = 3

n(D_r) < n(R_r)

D_r = A

R_r  = A

n(r) = 3

n(D_r) > n(R_r)

D_r = A

3 $$\in$$   R_r

n(r) = 3

D_r  -  R_r = {}

{(1, 0), (2, 1), (3, 0), (4, 3), (6, 5)}

{(2, 1), (4, 3), (6, 5)}

{(0, 0), (2, 1), (4, 3), (6, 5)}

{(5, 6)}

{(0, 0), (1, 0), (2, 2), (3, 1)}

{(1, 0), (2, 3), (3, 2)}

{(0, 0), (1, 0), (2, 3), (3, 2)}

{(2, 3), (3, 2)}

{ }

{(–1,0), (0, –1), (3,4)}

{(–1, –3), (0, –2), (1,0)}

{(–1, 1), (0, –3), (0, –2), (0,0)}