let x be the large number, and y be the smaller one: x=3+2y, 2x-5y=0 (from the question) --> substitute the first equation in the second --> 2(3+2y)-5y=0 --> 6+4y-5y=0 -->6-y=0 --> y=6, substitute y=6 in the first equation --> x=3+2(6) --> x=15. therefore the two numbers are 6,15