Question 938407
t + u = 12
u = {{{12-t}}}
...
10(12-t)+ t   -18 = 10t + (12-t)
120 -9t - 18 = 9t + 12
90 = 18t
5 = t  and u = 7
57 the number
...
And checking
70 + 5 - 18 = 57