Question

3 Вариант! до 24.01.21 плиз

3fd5bf04eebbcd3a13f63d5a2f7c1676.docx

Answer 1

Ответ:

Вариант 3

I.

$1)(x - 8)(x + 8) \\ x {}^{2} - 8x + 8x - 64 \\ x {}^{2} - 8 {}^{2} \\ x {}^{2} - 64 \\ 2)(2b - 5)(2b + 5) \\ (2b) {}^{2} - 5 {}^{2} \\ (2b) {}^{2} \\ 2 {}^{2} b {}^{2} \\ 4b {}^{2} \\ 4b {}^{2} - 5 {}^{2} \\ 4b {}^{2} - 25 \\ 3)( \frac{4}{9} y {}^{8} + 1.4x {}^{15} )(1.4x {}^{15} - \frac{4}{9} y {}^{8} ) \\ ( \frac{4}{9} y {}^{8} + \frac{7}{5} x {}^{15} )(1.4x {}^{15} - \frac{4}{9} y {}^{8}) \\ ( \frac{4}{9} y {}^{8} + \frac{7}{5} x {}^{15} )( \frac{7}{5} x {}^{15} - \frac{4}{9} y {}^{8} ) \\ ( \frac{7}{5} x {}^{15} + \frac{4}{9} y {}^{8} )( \frac{7}{5} x {}^{15} - \frac{4}{9} y {}^{8} ) \\ ( \frac{7}{5} x {}^{15} ) {}^{2} - ( \frac{4}{9} y {}^{8} ) {}^{2} \\ \frac{49}{25} x {}^{30} - ( \frac{4}{9} y {}^{8) {}^{2} }$

II.

$(2b + 6)(2b - 6) - 3b(2b + 3) \\ (2b + 6)(2b - 6) \\ (2b) {}^{2} - 6 {}^{2} \\ 4b {}^{2} - 6 {}^{2} \\ 4b {}^{2} - 36 \\ 4b {}^{2} - 36 - 3b \times (2b + 3) \\ 4b {}^{2} - 36 - 6b {}^{2} - 9b \\ 4b {}^{2} - 6b {}^{2} \\ (4 - 6)b {}^{2} \\ - 2b {}^{2} \\ - 2b {}^{2} - 36 - 9b \\ - 2b {}^{2} - 9b - 36$

III.

$2x(3 + 8x) - (4x - 3)(4x + 3) = 1.5 \\ 6x + 16x {}^{2} - (4x - 3)(4x + 3) = 1.5 \\ 6x + 16x {}^{2} - (16x {}^{2} - 9) = 1.5 \\ 6x + 16x {}^{2} - 16x {}^{2} + 9 = 1.5 \\ 6x + 9 = 1.5 \\ 6 x = 1.5 - 9 \\ 6x = - 7.5 \\ x = - 1.25 \\ x1 = - \frac{5}{4} \\ x2 = - 1 \frac{1}{4}$