2x/3x 2x+4/3x+4=5/7 cross multiply 7(2x+4)=5(3x+4) 14x+28=15x+20 x=8 the original numbers are 16 and 24, their sum is 40

x/y = 2/3; => 3x = 2y;=> x = (2y)/3; (x+4)/(y+4) = 5/7=> 7x + 28 = 5y + 20 => 7x - 5y = -8 => (14y)/3 - 5y = -8 => 14y - 15y = -24 => y = 24 => x = 16 => x + y = 40;