А) 5m/7m = 5/7
б) mpq/mnq = p/n
в) (p^2+pc)/pb = (p(p+c))/pb = (p+c)/b
г) (p^2 - c^2) / (p^2 - pc) = ((p-c)(p+c)) / p(p-c) = (p+c) / p
д) (a^2+3a) / (a^2-9) = (a(a+3)) / ((a-3)(a+3)) = a/(a-3)
е) (ax - bx + a - b) / (ay-by+a-b) = (x(a-b)+a-b) / (y(a-b)+a-b) = x+a-b/y+a-b
ё) (x^2-16y^2) / (4y-x) = ((x-4y)(x+4y)) / 4y - x = -( ((x-4y)(x+4y)) / (x - 4y) ) = - (x+4y) = -x -4y