Question 321399
the number is 10t + u


t = u + 1


10t + u + 10u + t = 77 ___ 11t + 11u = 77 ___ t + u = 7


substituting ___ (u + 1) + u = 7 ___ u = 3


substituting ___ t = (3) + 1 = 4


the number is 43