[(4m)/(m^2-4)+(m-2)/(m+2)]/[1/(m^2-4)]=[(4m)/(m^2-4)+(m-2)/(m+2)]*(m^2-4)=(4m)/(m^2-4)*(m^2-4)+(m-2)/(m+2)*(m^2-4)=4m+(m-2)/(m+2)*(m-2)(m+2)=4m+(m-2)²=4m+m²-4m+4=m²+4