Ответ:

1. a)1/m-7 b)a²-ab/2b³

2. a)3/x+y b) a-4

Объяснение:

a) m-2/m²-49 * m+7/m-2 = m-2/(m-7)(m+7) * m+7/m-2

= 1/m-7

b) ab-b²/8 * 4a/b⁴ = b(a-b)/2 * a/b⁴ = a-b/2 * a/b³

= a(a-b)/2b³ = a²-ab/2b³

a) x-y/xy : x²-y²/3xy = x-y/xy * 3xy/(x-y)(x+y) = 3/x+y

b) a²-16/a-3 : a+4/a-3 = (a-4)(a+4)/a-3 * a-3/a+4 = a-4