Question 14450
let the smaller number be x and greater number be y.
sum of numbers = x+y = 18.......(1)
three times the greater number = 3*y
four times the smaller number = 4*x
three times the greater number exceeds four times the smaller number by 5 
hence 3*y-4*x=5
     -4*x+3*y=5 .........(2).we have 2 unknowns.let us eliminate one unknown say x.for this multiply eqn.(1) with 4 and add to eqn.(2).
 eqn.(1)*4 gives us ....4*x+4*y=4*18=72.......(3)adding to eqn.(2)
                       -4*x+3*y=5......(2) we get 
                      4*y+3*y=7*y=72+5=77
                            y=77/7=11  substituting in 1 we get 
                         x+11=18 or x=18-11=7