Question

номер:529 (1), 530(1), 531(1)

Answer 1

529.  7x/2(x-1)+5x/x-1=7x=10x/2(x-1)=17x/2x-1
530.   1/2a-b-1/2a-b=0
531.   2m/5m+5n + 3n/5m+5n =2m(5m-5n)+3n(5m+5n)=
=10m^2-10mn+15mn+15n^2 / (5m+5n)(5m-5n)=10m^2+5mn+15n^2 / 25m^2-25n^2