[tex]1. \: {x}^{2} + 3 = 4x \\ {x}^{2} - 4x + 3 = 0 \\ {x}^{2} - 3x - x + 3 = 0 \\ x(x - 3) - 1 (x - 3) \\ (x - 1)(x - 3) \\ x = 1 \: i \: x = 3 \\ [/tex]
[tex]2. \: 2 - x + 5 = 10 \\ - x = 3 \\ x = - 3 \\ [/tex]
[tex]3. \: 3x + 1 = x + 7 \\ 3x - x = 7 - 1 \\ 2x = 6 \\ x = 3[/tex]
[tex]4. \: 2 = 8(sprzeczne)[/tex]
1. Prawda
2. Fałsz
3. Fałsz