Question 1034883
{{{a[35] = a[23] + 12d = 2/3 + 12d}}} and {{{a[35] = a[53] - 18d = 3/2 - 18d}}}.

Subtract the first equation from the second equation, giving {{{5/6 - 30d = 0}}}, or {{{d = 1/36}}}.

==> {{{a[35] = a[23] + 12d = 2/3 + 12*(1/36) = 1}}}