Răspuns:
[tex]c) {3x}^{2} = 0 \\ d = 0 { }^{2} - 4 \times 3 \times 0 \\ d = 0[/tex]
[tex]b) \: \: \: x {}^{2} + 5 = 15 \\ x {}^{2} = 15 - 5 \\ x { }^{2} = 10 \\ x = \sqrt{10} [/tex]
