Answer:
[tex]s - t = 2 \\ 2t + s = 17 \\ \\ s - t - (2t + s) = 2 - 17 \\ s - t - 2t - s = - 15 \\ - 3t = - 15 \\ \frac{ - 3t}{ - 3} = \frac{ - 15}{ - 3} \\ t = 5 \\ \\ 2t + s = 17 \\ 2 \times 5 + s = 17 \\ 10 + s = 17 \\ s = 17 - 10 \\ s =7 \\ \\ s - t = 2 \\ 7 - 5 = 2 \\ 2 = 2[/tex]