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)

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

Answer 2

спасибо