Question

20. Rezolvaţi ecuațiile:


$x {}^{2} = 7 + 4 \sqrt{3}$
$x {}^{2} = 4 - 2 \sqrt{3}$
Vă rog repede​

Answer 1

Explicație pas cu pas:

$1.x {}^{2} = 7 + 4 \sqrt{3} \\ x {}^{2} = 7 {}^{2} +( 4 \sqrt{3} ) {}^{2} \\ x {}^{2} = 49 + </strong><strong>48</strong><strong>\\ x {}^{2} = </strong><strong>92</strong><strong>\\ x = \sqrt{</strong><strong>92</strong><strong>} \\ \\ 2.x {}^{2} = 4 - 2 \sqrt{3} \\ x {}^{2} = 4 {}^{2} - (2 \sqrt{3} ) {}^{2} \\ x {}^{2} = 16 - 8 \\ x {}^{2} = 8 \\ x = \sqrt{8} \\ x = 2 \sqrt{2}$