Question

solve by cramers rule 3x-4y=7 ; 5x+2y=3 ​

Answer 1

3x-4y=7
5x+2y=3

D=|3 -4|=6+20=26
|5 2|

Dx=|7 -4|=14+12=26
|3 2|

Dy=|3 7|=9-35=-26
|5 3|

by cramers rule
x=Dx/D=26/26=1

y=Dy/D=-26/26=-1

(x,y)=(1,-1)

Answer 2

Answer:

x = 1 and y = -1

Given:

3x - 4y = 7

5x + 2y = 3

Step-by-step explanation:

According to cremer's rule,

x = $\frac{D_{x} }{D}$

y =  $\frac{D_{y} }{D}$

let us first find $D, D_{x}, D_{y}$.

$D = \left[\begin{array}{cc}3&-4\\5&2\\\end{array}\right]$

$D$ = (3 × 2) - (5 × -4) = 6 - (-20) = 26

$D_{x} = \left[\begin{array}{cc}7&-4\\3&2\\\end{array}\right]$

$D_{x}$ = (7 × 2) - (3 × -4) = 14 - (-12) = 26

$D_{y} = \left[\begin{array}{cc}3&7\\5&3\\\end{array}\right]$

$D_{y}$ = (3 × 3) - (5 × 7) = 9 - (35) = -26

$D, D_{x}, D_{y}$

So,

x = $\frac{D_{x} }{D}$

x = $\frac{26}{26}$

x = 1

y =  $\frac{D_{y} }{D}$

x = $\frac{-26}{26}$

x = -1

Then,

x = 1 and y = -1.

Hence, x = 1 and y = -1 are solution of system of equations.

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