Question

решите пожалуйста очень нужно​

Answer 1

а)

${x}^{2} - (x + 3)(x - 3) = 3x \\ {x}^{2} - ( {x}^{2} - 9) = 3x \\ {x}^{2} - {x}^{2} + 9 = 3x \\ 9 = 3x \\ 3x = 9 \\ x = \frac{9}{3} \\ x = 3$

б)

$4 {x}^{2} - 9 = 0 \\ 4 {x}^{2} = 9 \\ {x}^{2} = \frac{9}{4} \\ {x}^{2} = 2.25 \\ x = \sqrt{2.25} \\ x_1 = 1.5 \\ x_2 = - 1.5$

в)

${x}^{2} - (x - 4)(x + 4) = 2x \\ {x}^{2} - ( {x}^{2} - 16) = 2x \\ {x}^{2} - {x}^{2} + 16 = 2x \\ 16 = 2x \\ 2x = 16 \\ x = \frac{16}{2} \\ x = 8$

г)

$25 {x}^{2} - 16 = 0 \\ 25 {x}^{2} = 16 \\ {x}^{2} = \frac{16}{25} \\ {x}^{2} = 0.64 \\ x = \sqrt{0.64} \\ x_{1} = 0.8 \\ x_{2} = - 08$