Question

Выполните умножение дробей а)9с^3/а*а^2/12с^3 б)а^4с/8b*12b^3/a^3c^4 в)6x*b^5/3b3 выполните действия а)(3/x-3-x+15/x^2-9):x/x+3 b)(4/y-2/y-5):y/y^2-25+5/y+5 Срочно!!!

Answer 1

а)$frac{9c^3}{a}* frac{a^2}{12c^3}= frac{9c^3a^2}{12ac^3}= frac{3a}{4}$
б)$frac{a^4c}{8b}* frac{12b^3}{a^3c^4} = frac{12a^4b^3c}{8a^3bc^4} = frac{3ab^2}{2c^3}$
в)$frac{6xb^5}{3b^3}=2xb^2$
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а)$( frac{3}{x-3} - frac{x+15}{x^2-9}): frac{x}{x+3} = frac{3(x+3)-x-15}{(x-3)(x+3)}: frac{x}{x+3}= frac{(2x-6)(x+3)}{(x-3)(x+3)x}= frac{2(x-3)}{x(x-3)}= frac{2}{x}$
b)$(frac{4}{y}- frac{2}{y-5}): frac{y}{y^2-25}+ frac{5}{y+5}= frac{4y-20-2y}{y(y-5)}: frac{y}{(y-5)(y+5)}+ frac{5}{y+5}$$= frac{(2y-20)(y-5)(y+5)}{y^2(y-5)}+ frac{5}{y+5}= frac{(2y-20)(y+5)}{y^2}+ frac{5}{y+5}= frac{(2y-20)(y+5)^2+5y^2}{y^2(y+5)}=$$frac{(2y-20)(y+5)^2+5y^2}{y^2(y+5)}= frac{2y^3+20y^2+50y-20y^2-200y-500}{y^2(y+5)}= frac{2y^3-150y-500}{y^2(y+5)}$