Question

3x-y =5,4x+5y =1 then x =___, y=___

Answer 1

Answer:

x = 26 / 19

y = - 17 / 19

Step-by-step-explanation:

The given linear equations are

3x - y = 5

⇒ 3x - 5 = y

⇒ y = 3x - 5 - - - ( 1 ) &

4x + 5y = 1

⇒ 4x + 5 ( 3x - 5 ) = 1 - - - [ From ( 1 ) ]

⇒ 4x + 15x - 25 = 1

⇒ 19x = 1 + 25

⇒ 19x = 26

⇒ x = 26 / 19

Now, by substituting x = 26 / 19 in equation ( 1 ),

y = 3x - 5 - - - ( 1 )

⇒ y = 3 * ( 26 / 19 ) - 5

⇒ y = ( 78 / 19 ) - 5

⇒ y = ( 78 - 95 ) / 19

⇒ y = - 17 / 19

∴ The solution of the given equations is

( x, y ) = ( 26 / 19, - 17 / 19 ).

Answer 2

Answer:

3x - y = 5.

3x - 5 = y.

• => y = 3x - 5. ---------(i)

4x + 5y = 1.

4x + 5(3x - 5) = 1. [ from eqn. (i) ].

4x + 15x - 28 = 1.

19x = 1 + 25.

19x = 26.

• => x = 26/19.

y = 3x - 5.

y = 3(26/19) - 5.

y = (78/19) - 5.

y = (78 - 95)/19.

• => y = -17/19.

Hence, the values of x and y are:-

• x = 26/19.
• y = -17/19.