Question

solve the following systems of equations x minus 2 Y equal to zero and 3 X + 4 Y equal to 20

Answer 1

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Method 1 :



x - 2y = 0 -------: ( 1 )

3x + 4y = 20 -----: ( 2 )




On ( 1 ) , multiply by 2 on both siddes ,

= > 2 × ( x - 2y ) = 2 × 0

= > 2x - 4y = 0 ------: ( 3 )




Adding ( 2 ) & ( 3 )

3x + 4y =20
2x - 4y = 0
_________
5x = 20
_________


= > 5x = 20

= > 5 × x = 5 × 4

= > x = 4


Value of x = 4




Putting the value of x in ( 1 ) ,



= > x - 2y = 0

= > 4 - 2y = 0

= > 4 = 2y

= > 2 × 2 = 2 × y

= > 2 = y



Hence,
$\textbf{ Value of x = 4}\\ \mathbf{ value of y = 2 }$





Method 2 :



= > x - 2y = 0

= > x = 2y -----: ( 1 )



Putting the value of x in other equation ,


= > 3x + 4y = 20

= > 3( 2y ) + 4y = 20

= > 6y + 4y = 20

= > 10y = 20

= > 10 × y = 10 × 2

= > y = 2



Putting value of y in ( 1 ) ,


= > x = 2y

= > x = 2( 2 )

= > x = 4


Hence,
$\textbf{ Value of x = 4} \\ \mathbf{ value of y = 2 }$







From both the methods,
Value of x = 4
Value of y = 2

Answer 2

Answer:

The equation has the value of x equal to 4 and y equal to 2.

Step-by-step explanation:

Given

Equation is,

$x-2y=0----eq.i\\3x+4y=20----eq.ii$

To find the value of x and y

Solution:

From eq. i

x-2y=0

⇒x=2y

Putting the value of x in eq. ii

3x+4y=20

⇒6y+4y=20

⇒10y=20

⇒y=2

Substituting the value of y in eq. i

x-2y=0

x-2×2=0

⇒x-4=0

⇒x=4

Hence, the value of x is 4 and y is 2.