(x+3)/(2x-4)÷[(x十2)一5/(x一2)] =(x+3)/2(x-2)÷[(x^2-4一5)/(x一2)] =(x+3)/[2(x^2-9)] =(x+3)/[2(x-3)(x+3)] =1/[2(x-3)] =1/[2(3十根号2-3)] =1/[2(根号2)] =(根号2)/4
