The point of intersection of the graphs of the equations 3x — 5y = 19 and 3y —7x + 1 =0 is P$$\left(\alpha,\beta\right)$$ . Whatis the value of $$ \left(3\alpha -\beta \right)$$ ?

The point of intersection of the graphs of the equations 3x — 5y = 19 and 3y —7x + 1 =0 is P$$\left(\alpha,\beta\right)$$
So,
3$$\alpha — 5\beta = 19$$ ---(1)
7$$\alpha — 3\beta = 1$$ ---(2)
Eq(1) multiply by 3 and eq (2) multiply by 5,
9$$\alpha — 15\beta = 57$$ ---(1)
35$$\alpha — 15\beta = 5$$ ---(2)
From eq (3) and (4),
26$$\alpha = -52$$
$$\alpha = -2$$
From eq (1),
3$$\times -2 - 5\beta = 19$$
$$\beta = -5$$
Now,
$$ \left(3\alpha -\beta \right)$$
= $$ \left(3\times -2 + 5s \right)$$
= -1