How do you solve using gaussian elimination or gauss-jordan elimination, 3x-4y=18, 8x+5y=1?

Jan 18, 2018

$x = 2$ and $y = - 3$

Explanation:

From first equation, $y = \frac{3 x - 18}{4}$

After plugging value of $y$ into second equation,

$8 x + 5 \cdot \frac{3 x - 18}{4} = 1$

$\frac{32 x + 15 x - 90}{4} = 1$

$\frac{47 x - 90}{4} = 1$

$47 x - 90 = 4$

$47 x = 94$, so $x = 2$

Thus, $y = \frac{3 \cdot 2 - 18}{4} = - 3$