Question

пожалуйста срочнооооо нужно умоляю срочно ООО даю 25 баллов ​

Answer 1

Номер 1

а)

$(7 \times 0.5 - 1) {}^{2} - 25 \times 0.5 {}^{2} = 2.5 {}^{2} - 25 \times \frac{1}{4} = \frac{25}{4} - \frac{25}{4} = 0$

Б)

$(9.3 - 3) {}^{2} - 12(9.3 - 3) + 36 = 6.2 {}^{2} - 12 \times 6.3 + 36 = \frac{3969}{100} - \frac{378}{5} + 36 = \frac{9}{100} = 0.09$

Номер 2

а)

$(2x - 5) {}^{2} = 9x {}^{2} \\ 4x - 20x + 25 - 9x {}^{2} = 0 \\ {x}^{2} + 5x - 5 - x = 0 \\ (x + 5)(x - 1) = 0 \\ x + 5 = 0 \\ x - 1 = 0 \\ x1 = - 5 \\ x2 = 1$

б)$(3a - 5) {}^{2} - (2a + 7)(2a - 7) = 74 \\ 9a {}^{2} - 30a + 25 - 4a ^{2} + 49 = 74 \\ 5a {}^{2} - 30a + 74 = 74 \\ 5a {}^{2} - 30a = 0 \\ 5a(a - 6) = 0 \\ a = 0 \\ a - 6 = 0 \\ a1 = 0 \\ a2 = 6$

Удачи!