1) 2x (2x + 3)² - (2x - 3) (4x² + 6x + 9)
- 2x(2x + 3)² - (2x - 3)(4x² + 6x + 9) = 2x(4x² + 12x + 9) - (8x³ - 12x² + 12x² - 18x + 18x - 27) = 8x³ + 24x² + 18x - (8x³ - 27) = 8x³ + 24x² + 18x - 8x³ + 27 = 24x² + 18x + 27
Ответ: 24x² + 18x + 27
2) $$ \frac{5x^3-5}{x+2} \cdot \frac{(x+1)^3-x}{13x+26} $$
- \(\frac{5x^3-5}{x+2} \cdot \frac{(x+1)^3-x}{13x+26} = \frac{5(x^3-1)}{x+2} \cdot \frac{x^3+3x^2+3x+1-x}{13(x+2)} = \frac{5(x-1)(x^2+x+1)}{x+2} \cdot \frac{x^3+3x^2+2x+1}{13(x+2)}\)
Ответ: $$\frac{5(x-1)(x^2+x+1)}{x+2} \cdot \frac{x^3+3x^2+2x+1}{13(x+2)}$$
3) $$(\frac{x-3}{x^2-3x+9} - \frac{6x-18}{x^3 + 27}) : \frac{5x-15}{4x^3+108}$$
- $$ (\frac{x-3}{x^2-3x+9} - \frac{6x-18}{x^3 + 27}) : \frac{5x-15}{4x^3+108} = (\frac{x-3}{x^2-3x+9} - \frac{6(x-3)}{(x+3)(x^2 -3x + 9)}) : \frac{5(x-3)}{4(x^3+27)} = \frac{(x-3)(x+3) - 6(x-3)}{(x+3)(x^2 -3x + 9)} : \frac{5(x-3)}{4(x+3)(x^2 -3x + 9)} = \frac{(x-3)(x+3 - 6)}{(x+3)(x^2 -3x + 9)} : \frac{5(x-3)}{4(x+3)(x^2 -3x + 9)} = \frac{(x-3)(x-3)}{(x+3)(x^2 -3x + 9)} \cdot \frac{4(x+3)(x^2 -3x + 9)}{5(x-3)} = \frac{4(x-3)}{5} $$
Ответ: $$\frac{4(x-3)}{5}$$
4) $$(\frac{1}{a^2+3a+2} + \frac{2a}{a^2+4a+3} + \frac{1}{a^2+5a+6})^2 \cdot \frac{(a-3)^2+12a}{2}$$
- $$(\frac{1}{(a+1)(a+2)} + \frac{2a}{(a+1)(a+3)} + \frac{1}{(a+2)(a+3)})^2 \cdot \frac{(a-3)^2+12a}{2} = (\frac{a+3+2a(a+2)+a+1}{(a+1)(a+2)(a+3)})^2 \cdot \frac{a^2 -6a + 9 + 12a}{2} = (\frac{a+3+2a^2+4a+a+1}{(a+1)(a+2)(a+3)})^2 \cdot \frac{a^2+6a+9}{2} = (\frac{2a^2+6a+4}{(a+1)(a+2)(a+3)})^2 \cdot \frac{(a+3)^2}{2} = (\frac{2(a^2+3a+2)}{(a+1)(a+2)(a+3)})^2 \cdot \frac{(a+3)^2}{2} = (\frac{2(a+1)(a+2)}{(a+1)(a+2)(a+3)})^2 \cdot \frac{(a+3)^2}{2} = (\frac{2}{a+3})^2 \cdot \frac{(a+3)^2}{2} = \frac{4}{(a+3)^2} \cdot \frac{(a+3)^2}{2} = \frac{4}{2} = 2$$
Ответ: 2
5) $$x - \frac{ax}{a-x} \cdot \frac{a+x}{a} - \frac{ax^2}{a^2-x^2}$$
- $$x - \frac{ax}{a-x} \cdot \frac{a+x}{a} - \frac{ax^2}{a^2-x^2} = x - \frac{x(a+x)}{a-x} - \frac{ax^2}{(a-x)(a+x)} = \frac{x(a-x)(a+x) - x(a+x)(a+x) - ax^2}{(a-x)(a+x)} = \frac{x(a^2-x^2) - x(a^2+2ax+x^2) - ax^2}{(a-x)(a+x)} = \frac{xa^2-x^3 - xa^2-2ax^2-x^3 - ax^2}{(a-x)(a+x)} = \frac{-2x^3 - 3ax^2}{(a-x)(a+x)} = \frac{-x^2(2x + 3a)}{(a-x)(a+x)}$$
Ответ: $$\frac{-x^2(2x + 3a)}{(a-x)(a+x)}$$
6) $$(\frac{a}{a+1} + 1) : (1 - \frac{3a^2}{1-a^2})$$
- $$(\frac{a}{a+1} + 1) : (1 - \frac{3a^2}{1-a^2}) = (\frac{a+a+1}{a+1}) : (\frac{1-a^2-3a^2}{1-a^2}) = (\frac{2a+1}{a+1}) : (\frac{1-4a^2}{1-a^2}) = \frac{2a+1}{a+1} : \frac{(1-2a)(1+2a)}{(1-a)(1+a)} = \frac{2a+1}{a+1} \cdot \frac{(1-a)(1+a)}{(1-2a)(1+2a)} = \frac{2a+1}{1} \cdot \frac{1-a}{(1-2a)(1+2a)} = \frac{(2a+1)(1-a)}{(1-2a)(1+2a)}$$
Ответ: $$\frac{(2a+1)(1-a)}{(1-2a)(1+2a)}$$