Let x = larger number
y = smaller number
x - y = 72
0.045x = 0.085y
Multiply the second equation by 1000:
x- y = 72
45x - 85y = 0
Multiply the first equation by -45, then add the equations:
-45x + 45y = -3240
45x - 85y = 0
-40y = -3240
y = 81 and x = 72 + y = 153