Question

What is the value of Dx for solving the simultaneous equations 3x+2y=11
and 7x-4y=9 by Cramer’s rule?

Answer 1

$\huge \star \huge\rm \: Solution$

 

 

 

By Cramer's rule ,

 

[tex] \sf \bold {D_ \bold{x} =

\left|

\begin{array}{cc}

\bold {\ c_{1} \: \: \: \: b_{1}} \\

\bold{c_{2} \: \: \: \: c_{2}}

\end{array}

\right| }[/tex]

‎ 

‎ 

[tex]\sf \bold{D_{x}} =

\left|

\begin{array}{cc}

\bold{11 \: \: \ \: \: \: 2\:}\\

\bold{ 9 \: \: \: \: \: ( - 4)}

\end{array}

\right| [/tex]

 

 

$\sf \bold D_{x} = [ \bold{11 \times ( - 4) ] - [9 \times 2}]$

 

‎ 

$\sf \bold{D_{x}} = \bold{ ( \bold - 44 \:)} \: - \bold{(18 )}</p><p>$

  

 

$\sf \pink{D_{x} = - \sf { 62}}$

Therefore, the value of Dx is -62 .

Answer 2

Step-by-step explanation:

D=3×(-4)-7×2

=-12-14

D= -26

Dx=2×9-(-4)×(-11)

=18-(-14)

18+44

Dx= -62