а) 12x/u^3 * 2y^4/9x^2= 24xy^4/9ux^2= 8y^4/3ux^2
б) 4a^2-1/a^2-9--a+3/6a+3= (4a^2 - 1)/(a^2 - 9) - (a - 3)/(6a + 3)= (4a + 1)(a - 1)/(a + 3)(a - 3) - (a - 3)/(3)(2a + 1)= (4a + 1)(a - 1)/(a + 3)(a - 3) - 1/(2a + 1)
в) x^2 + 2x + 4/6x^4 : x^3 - 8/2x^3= (x^2 + 2x + 4)/(6x^4) * (2x^3)/(x^3 - 8)= (2x^5 + 4x^4 + 8x^3)/(6x^4(x^3 - 8))= (2(x^3)(x^2 + 2x + 4))/(6x^4(x - 2)(x^2 + 2x + 4))= (2(x^3))/(6x^4(x - 2))= 1/(3x(x - 2))
а) 12x/u^3 * 2y^4/9x^2
= 24xy^4/9ux^2
= 8y^4/3ux^2
б) 4a^2-1/a^2-9--a+3/6a+3
= (4a^2 - 1)/(a^2 - 9) - (a - 3)/(6a + 3)
= (4a + 1)(a - 1)/(a + 3)(a - 3) - (a - 3)/(3)(2a + 1)
= (4a + 1)(a - 1)/(a + 3)(a - 3) - 1/(2a + 1)
в) x^2 + 2x + 4/6x^4 : x^3 - 8/2x^3
= (x^2 + 2x + 4)/(6x^4) * (2x^3)/(x^3 - 8)
= (2x^5 + 4x^4 + 8x^3)/(6x^4(x^3 - 8))
= (2(x^3)(x^2 + 2x + 4))/(6x^4(x - 2)(x^2 + 2x + 4))
= (2(x^3))/(6x^4(x - 2))
= 1/(3x(x - 2))