Question

3 x - 5 y - 4 = ,9x- 2y +1=0​

Answer 1

$3x - 5y = 4$

$9x - 2y = - 1$

by cramet's rule ( determinant method)

$d = | \frac{3}{ - 5} \frac{9}{ - 2} |$

$d = 3 \times - 2 - 9 \times - 5$

$= - 6 + 45$

$= 39$

$d_{x} = | \frac{4}{ - 1} \frac{9}{ - 2} |$

$= 4 \times - 2 + 5 \times - 1$

$= - 8 - 5$

$- 13$

$d_{y} = | \frac{3}{9} \frac{4}{ - 1} |$

$= 3 \times - 1 - 4 \times 9$

$= - 3 - 36$

$= - 39$

$x = \frac{ d_{x} }{d}$

$= \frac{ - 13}{39}$

$= \frac{ - 1}{3}$

$y = \frac{ d_{x} }{d}$

$= \frac{ - 39}{39}$

$= - 1$

$(x,y)=(-1/3,-1)$