Question

Надо сделать быстро!!!

Answer 1

Ответ:

1.

$a) - 12a {}^{2} + 18a {}^{2} = - 6a(2 - 3a) \\ б)2a + 4b - ab - 2b {}^{2} =2(a + 2b) - b(a + 2b) = (a +2b ) (2 - b) \\ в)x {}^{2} - 64y {}^{2} = (x - 8y)(x + y) \\ - 2x {}^{3} - 28x {}^{2} - 98x = -2 x(x {}^{2} + 14x + 49) = - 2x(x + 7) {}^{2} \\ д)a {}^{6} - 8b {}^{3} = (a {}^{2} ) {}^{3} - (2b) {}^{3} = (a {}^{2} - 2b)((a {}^{2} ) {}^{2} + a {}^{2} \times 2b +( 2b) {}^{2} ) = (a {}^{2} - 2b)(a {}^{4} + 2a {}^{2} b + 4b {}^{2}$

2.

$(x - 4) {}^{2} - 25 = 0 \\ x {}^{2} - 8x + 16 - 25 = 0 \\ x {}^{2} - 8x - 9 = 0 \\ a = 1 \: b = - 8 \: c = - 9 \\ D = b {}^{2} - 4ac = ( - 8) {}^{2} - 4 \times 1 \times ( - 9) = 64 + 36 = 100 = 10 {}^{2} \\ x = \frac{ - b ± \sqrt{D} }{2a} = \frac{8±10}{2} = 9 \: \: и -1$

$(3xy + 1)(3x + y) - y(3x + y) {}^{2 }\\ (3x + y)(3xy + 1 - y(3x + y)) \\ (3x + y)(3 xy + 1 - 3xy - y {}^{2} ) \\ (3x + y)(1 - y)(1 + y)$

$\frac{182 {}^{3} + 62 {}^{3} }{244} - 182 \times 62 = \frac{(182 + 62)(33124 - 11284 + 3844)}{244} - 11284 = \frac{244(33124 - 11284 + 3844)}{244} - 11284 = 33124 - 11284 + 3844 - 11284 = 14400$