ПОМОГИТЕ ПОЖАЛУЙСТА. Я не успеваю, очень благодарен буду. Помогите.

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57) 4x/x^2-y^2  -  4/x+y=  4x/(x-y)(x+y)  -  4/(x+y)= (4x - 4(x-y))/(x+y)(x-y)= (4x-4x+4y)/(x+y)(x-y)= 4y/(x+y)(x-y) 58) 3c/(a^2-c^2)   -   2/(a-c)= 3c/(a+c)(a-c)  -  2/(a-c)= (3c-2(a+c))/(a+c)(a-c)= (3c-2a-2c)/(a+c)(a-c)= (c-2a)/(a+c)(a-c) 59) a/(a-b)  -  (a-b)/(a+b)= (a(a+ab)-(a-b)^2)/(a+b)(a-b)= (a^2+ab-a^2+2ab-b^2)/(a+b)(a-b)=(3ab-b^2)/(a+b)(a-b) 60)(x-y)/(x+y)  -  y/(x-y)= ((x-y)^2 -y(x+y))/(x+y)(x-y)=(x^2-2xy+y^2-yx-y^2)/(x+y)(x-y)=(x^2-3xy)/(x+y)(x-y) 61)(3b^2+2b)/(b^2-4)  -  b(b-2)= (3b^2+2b)/(b-2)(b+2) - b/(b-2)= (3b^2+2b-b(b+2))/(b-2)(b+2)=(3b^2+2b-b^2-2b)/(b-2)(b+2)= 2b^2/(b-2)(b+2) 62)(3a^2+6a)/(a^2-9)  -  2a/(a-3)= (3a^2+6a-2a(a+3))/(a-3)(a+3)= (3a^2+6a-2a^2-6a)/(a+3)(a-3)=a^2/(a+3)(a-3)