3a-3b/10ab · 25a^2b^3/a^2-b^2
=3(a-b)/10ab· 25ab(ab^2)/(a+b)(a-b)
=3(a-b)/2*5ab· 5*5ab(ab^2)/(a+b)(a-b)
=3*5(ab^2)/2(a+b)
=15ab^2/2a+2
3a-3b/10ab · 25a^2b^3/a^2-b^2
=3(a-b)/10ab· 25ab(ab^2)/(a+b)(a-b)
=3(a-b)/2*5ab· 5*5ab(ab^2)/(a+b)(a-b)
=3*5(ab^2)/2(a+b)
=15ab^2/2a+2