Question

Scrieti sub forma cea mai simpla opusul numarului real x la puterea 3 in urmatoarele cazuri:

x=3 radical 18-2 radical 72+radical 98
x=radical 12-5 radical 27 +2 radical 75
x=-radical 20-3 radical 45+2 radical 125
x=-2 radical 54 + 5 radical 24- radical 150


AJUTOR!!!!!

Answer 1

$1)x = 3 \sqrt{18} - 2 \sqrt{72} + \sqrt{98}$

$x = 3 \times 3 \sqrt{2} - 2 \times 6 \sqrt{2} + 7 \sqrt{2}$

$x = 9 \sqrt{2} - 12 \sqrt{2} + 7 \sqrt{2}$

$x = 4 \sqrt{2}$

${x}^{3}=4\sqrt{2}\times4\sqrt{2}\times4\sqrt{2}$

$64\sqrt{8}$

$64×2\sqrt{2}$

$128\sqrt{2}$

$-{x}^{3}=-128\sqrt{2}$
$2)x = \sqrt{12} - 5 \sqrt{27} + 2 \sqrt{75}$

$x = 2 \sqrt{3} - 5 \times 3 \sqrt{3} + 2 \times 5 \sqrt{3}$

$x = 2 \sqrt{3} - 15 \sqrt{3} + 10 \sqrt{3}$

$x = - 3 \sqrt{3}$

${x}^{3}=-3\sqrt{3}\times(-3\sqrt{3})\times(-3\sqrt{3})$

${x}^{3}=-27\sqrt{27}$

${x}^{3}=-27\times3\sqrt{3}$

${x}^{3}=-81\sqrt{3}$

$-{x}^{3}=-(-81\sqrt{3})$

$-{x}^{3}=81\sqrt{3}$

$3)x = - \sqrt{20} - 3 \sqrt{45} + 2 \sqrt{125}$

$x = - 2 \sqrt{5} - 3 \times 3 \sqrt{5} + 2 \times 5 \sqrt{5}$

$x = - 2 \sqrt{5} - 9 \sqrt{5} + 10 \sqrt{5}$

$x = - \sqrt{5}$

${x}^{3}=-\sqrt{5}\times(-\sqrt{5})\times(-\sqrt{5})$

${x}^{3}=-\sqrt{125}$

${x}^{3}=-5\sqrt{5}$

$-{x}^{3}=-(-5\sqrt{5})$

$-{x}^{3}=5\sqrt{5}$

$4)x = - 2 \sqrt{54} + 5 \sqrt{24} - \sqrt{150}$

$x = - 2 \times 3 \sqrt{6} + 5 \times 2 \sqrt{6} - 5 \sqrt{6}$

$x = - 6 \sqrt{6} + 10 \sqrt{6} - 5 \sqrt{6}$

$x = - \sqrt{6}$

${x}^{3}= - \sqrt{6} \times (-\sqrt{6}) \times (-\sqrt{6})$

${x}^{3}=-\sqrt{216}$

${x}^{3}=-6\sqrt{6}$

$-{x}^{3}=-(-6\sqrt{6})$

$-{x}^{3}=6\sqrt{6}$

Answer 2

A))
X= 9radical 2 -12radical2 + 7radical 2
X= 4radical 2
X^3= 64radical 8
X^3= 128radical 2
-X^3=-128radical2
B))
X= 2radical3 - 15radical3 +10radical3
X= -3radical3
X^3 = -27radical 27
-X^3= 81radical3
C)))
X= -2radical5-9radical5+10radical5
X= -radical5
X^3= -radical125
-X^3= 5radical5
D))
X=-6radical6 +10radical6-5radical6
X= -radical6
X^3= -radical216
-X^3= 6radical6
Sper ca te-am ajutat !