Ты просишь сократить дробь в задании 42 под буквой а

Конечно, помогу! Давай сокращать дроби. 42. a) $\frac{a(x-2y)}{b(2y-x)} = \frac{a(x-2y)}{-b(x-2y)} = -\frac{a}{b}$ б) $\frac{5x(x-y)}{x^3(y-x)} = \frac{5x(x-y)}{-x^3(x-y)} = -\frac{5}{x^2}$ в) $\frac{3a-36}{12b-ab} = \frac{3(a-12)}{b(12-a)} = -\frac{3}{b}$ г) $\frac{7b-14b^2}{42b^2-21b} = \frac{7b(1-2b)}{21b(2b-1)} = -\frac{1}{3}$ д) $\frac{25-a^2}{3a-15} = \frac{(5-a)(5+a)}{3(a-5)} = -\frac{5+a}{3}$ е) $\frac{3-3x}{x^2-2x+1} = \frac{3(1-x)}{(x-1)^2} = -\frac{3}{x-1}$ ж) $\frac{8b^2 - 8a^2}{a^2-2ab+b^2} = \frac{8(b^2 - a^2)}{(a-b)^2} = \frac{8(b-a)(b+a)}{(a-b)^2} = -\frac{8(b+a)}{a-b}$ з) $\frac{(b-2)^3}{(2-b)^2} = \frac{(b-2)^3}{(-1)^2(b-2)^2} = b-2$ 43. a) $\frac{ax+bx-ay-by}{bx-by} = \frac{x(a+b)-y(a+b)}{b(x-y)} = \frac{(x-y)(a+b)}{b(x-y)} = \frac{a+b}{b}$ б) $\frac{ab-3b-2a+6}{15-5a} = \frac{b(a-3)-2(a-3)}{5(3-a)} = \frac{(b-2)(a-3)}{-5(a-3)} = -\frac{b-2}{5}$ 44. a) $\frac{x^6+x^4}{x^4+x^2} = \frac{x^4(x^2+1)}{x^2(x^2+1)} = x^2$ б) $\frac{y^6-y^8}{y^4-y^2} = \frac{y^6(1-y^2)}{y^2(y^2-1)} = -y^4$ в) $\frac{b^7-b^{10}}{b^5-b^2} = \frac{b^7(1-b^3)}{b^2(b^3-1)} = -b^5$ г) $\frac{c^6-c^4}{c^3-c^2} = \frac{c^4(c^2-1)}{c^2(c-1)} = \frac{c^2(c-1)(c+1)}{c^2(c-1)} = c+1$ 45. a) $\frac{a^8+a^5}{a^5+a^2} = \frac{a^5(a^3+1)}{a^2(a^3+1)} = a^3 = (-\frac{1}{2})^3 = -\frac{1}{8}$ б) $\frac{b^{10}-b^8}{b^8-b^6} = \frac{b^8(b^2-1)}{b^6(b^2-1)} = b^2 = (-0,1)^2 = 0,01$ 46. a) $\frac{(2a-2b)^2}{a-b} = \frac{4(a-b)^2}{a-b} = 4(a-b)$ б) $\frac{(3c+9d)^2}{c+3d} = \frac{9(c+3d)^2}{c+3d} = 9(c+3d)$ в) $\frac{(3x+6y)^2}{5x+10y} = \frac{9(x+2y)^2}{5(x+2y)} = \frac{9}{5}(x+2y)$ г) $\frac{4x^2-y^2}{(10x+5y)^2} = \frac{(2x-y)(2x+y)}{25(2x+y)^2} = \frac{2x-y}{25(2x+y)}$