А5. (4-a)/(a-3) + (2a-5)/(-(a-3)=(-4+a+2a-5)/(a-3)=(3a-9)/(a-3)=(3(a-3))/(a-3)=3 ответ номер2
А6. (a^2-b^2)/ab * 3ab/(a+b)=(a-b)(a+b))/ab *3ab/(a+b)=3(a-b) ответ номера
В1. сокращаем 14 и 7и иксы,
((x-3)(x+3))/(-2x(x-3)=(x+3)/-2x
B2. (x+5)^2/(x(x+5) * x^3/(x-5)(x+5)=x^2/(x-5)
B3. (c-d)(c+d))/(c-d)(c-d)=(c+D)/(c-d)
B4. (10y+7y)/2(y-1)=17y/2(y-1)