Find the ordered pair (s, t) that satisfies the system
(s/2) + 5t =3 - 7t + 8s
3t - 6s = 9 - 2t
(s/2) + 5t = 3 - 7t + 8s → s + 10t = 6 - 14t + 16s → -15s + 24t = 6 (1)
3t - 6s = 9 -2t → 6s + 5t = 9 (2)
Multiply (1) by 6 and (2) by 15
-90s + 144t = 36
90s + 75t = 135 add these
219 t = 171
t = 171 / 219 = 57 / 73
6s + 5(57/73) = 9
6s + 285/73 = 9
6s = 9 - 285/73
6s = 372/73
s = 62 / 73