Răspuns:
7.
[tex] \sqrt{23.04} = 4.8[/tex]
[tex] {x}^{2} = 0.3 \times 4.8[/tex]
[tex] {x}^{2} = 1.44 \: = > x = 1.2[/tex]
8.
[tex]ab = \sqrt{81} = 9 \: = > \sqrt{ab} = 3[/tex]
[tex]ac = \sqrt{144} = 12 \: = > \sqrt{ac} = 2 \sqrt{3} [/tex]
[tex] \sqrt{ac} \times \sqrt{ab} = 3 \times 2 \sqrt{3} = 6 \sqrt{3} [/tex]