Let L=Luis age and V=Vanesas age They have an age difference of L-V=26 years(1)
Some years later it will be L=3V(2) so the (1) will be after substituting where L by 3V; 3V-V=26
2V=26 V=26/2=13 That means that it will happen when Vanessa will be 13 years old. Since she is now
4 years old, that will happen 13-4 = 9 years later (when she will be 13) Luis will be 30+9=39 years of age
check; 39=3 x 13