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1) Non

[tex]2*sqrt{1000} = \sqrt{4}*\sqrt{1000} = \sqrt{4*1000} = \sqrt{4000}[/tex]

 

2) [tex]\sqrt{2000} = \sqrt{400 * 5} = \sqrt{400} * \sqrt{5} = 20\sqrt{5} \\\sqrt{1000}=\sqrt{10 * 100} = \sqrt{100}*\sqrt{10} = 10\sqrt{10}[/tex]

 

3) [tex]A = \sqrt{2000} * \sqrt{1000} \\A = \sqrt{2000 * 1000} \\A = \sqrt{2000000} \\A = \sqrt{2 * 1000000} \\A= \sqrt{1000000} * \sqrt{2} \\A = 1000\sqrt{2}[/tex]

 

4) [tex]P = 2\sqrt{2000} + 2\sqrt{1000} \\P = 2 * 20\sqrt{5} + 2*10\sqrt{10} \\P = 20\sqrt{5}(2 + \sqrt{2}) \\ \\Car \\20\sqrt{5}*2= 40\sqrt{5} = 2*20\sqrt{5} \\20\sqrt{5}*\sqrt{2} = 20\sqrt{5*2}=20\sqrt{10} = 2*10\sqrt{10}[/tex]

1) racine(2000) = racine(2) x racine(1000) ce qui est different de 2 x racine(1000)

 

Donc non.

2) racine (2000) = racine (400 x 5) = racine (400) xR(5)= 20 x R(5)

R(1000) = 10 x R(10)

 

3)

A (aire) = longeur x largeur =R(2000) x R(1000) et tu reduis