Find the ordered pair $(s, t)$ that satisfies the system \begin{align*}
\dfrac{s}{2} + 5t &= 3,\\
3t - 6s &= 9.
\end{align*}

Step-by-step explanation:

The given system of equations is presented as follows;

3·t - 6·s = 9

Making t the subject of both equations, gives;

In the first equation; t = (3 - s/2)/5

In the second equation; t = (9 + 6·s)/3

Equating both values of t to find the the values that satisfies both equations, gives;

(3 - s/2)/5 = (9 + 6·s)/3

3 × (3 - s/2) = 5 × (9 + 6·s)

9 - (3/2)·s = 45 + 30·s

45 - 9 = (30 + (3/2))·s

36 = (63/2)·s

s = 36/(63/2) = 8/7

t = (3 - s/2)/5

∴ t = (3 - (8/7)/2)/5 = 17/35

Therefore, the ordered pair is (8/7, 17/35)