Ответ:

2(b-a)

1/2a

(a-b)/((a-b)(a+b))

(7*a*b+3)/(2*b)

(35*(b-c)*(b-c))/((45-b)(a-4))

4*a*b-sqrt(a*a)

sqrt(4*b*sqrt(b-a))

cos(x*x*x)

tg(sqrt(x*x))

sqrt(sin(x*x))