Выполните действия: 1) m/n − m/(m + n); 2) a/(a − 3) − 3/(a + 3); 3) c/(3c − 1) − c/(3c + 1); 4) x/(2y + 1) − x/(3y − 2).

\(\dfrac{m(m+n)-mn}{n(m+n)}=\dfrac{m^2}{n(m+n)}\).

\(\dfrac{a(a+3)-3(a-3)}{(a-3)(a+3)}=\dfrac{a^2+9}{a^2-9}\).

\(\dfrac{c(3c+1)-c(3c-1)}{(3c-1)(3c+1)}=\dfrac{2c}{9c^2-1}\).

\(\dfrac{x(3y-2)-x(2y+1)}{(2y+1)(3y-2)}=\dfrac{x(y-3)}{(2y+1)(3y-2)}\).