Question

To solve x + y = 4 , 3x - 2y = 4 by determinant method find the value of d? a) 2 b) 0 c) 3 d) -5​

Answer 1

$x + y = 4$

$comparing \: above \: equation \: with \: a_{1} + b_{1} = c_{1}$

$we \: get \: a_{1} = 1 \: b_{1} = 1 \: c_{1} = 4$

$3x - 2y = 4$

$comparing \: above \: equation \: with \: a2 + b2 = c2$

$we \: get \: a2 = 3 \: \: b2 = - 2 \: \: c2 = 4$

$d = | \frac{a1}{a2} \frac{b1}{b2} |$

$d= | \frac{1}{3} \frac{1}{ - 2} |$

$d= 1 \times - 2 - 1 \times 3$

$d = - 2 - 3$

$d = - 5$

$so \: correct \: ans \: is \: option \: (d)$