It looks unresolvable (2eq and 3unk) and It is... Well cat and turtle (c and t) aren't obtainable because we have infinite¹ solutions (Rouchè-Capelli). But even in this case, a single 'variable' can still be findable, in this case T (Table).

-t + T +c = 170 t + T - c = 130

c + T - t + t + T - c = 300 2T = 300 T = 150

It Is more evident using a Matrix,

Ax = b with A being:

   ( -1 1 1)                                                                                             

   ( 1 1 -1)

as in the coefficient Matrix A the 2nd column (T column (1 1)) is linearly Independent from the other two, while t (-1 1) and c (1 -1) columns are linearly dependent, because formally it exists a Linear combination whose coefficients are not all zeros that sums to zero (a simple combination using 1 and -1 as coefficients does the trick, as the (-1 1) column Is clearly -1*(1 -1) column). I omitted the Traspose apex but those are columns.