Question

*Which of the following is a solution of x+7y=10 and 3x-2y=7?*

1️⃣ (3,2)
2️⃣ (3,3)
3️⃣ (3,1)
4️⃣ (3,0)​

Answer 1

Answer:

The solution of the given simultaneous equations is ( x, y ) = ( 3, 1 ).

Option ( 3 )

Step-by-step-explanation:

The given simultaneous equations are

x + 7y = 10 and 3x - 2y = 7.

x + 7y = 10 - - ( 1 )

3x - 2y = 7 - - ( 2 )

Now,

x + 7y = 10 - - ( 1 )

⇒ x = 10 - 7y - - ( 3 )

Now,

3x - 2y = 7 - - ( 2 )

⇒ 3 * ( 10 - 7y ) - 2y = 7 - - [ From ( 3 ) ]

⇒ 30 - 21y - 2y = 7

⇒ 30 - 23y = 7

⇒ - 23y = 7 - 30

⇒ - 23y = - 23

⇒ 23y = 23

⇒ y = 23 ÷ 23

⇒ y = 1

Now, by substituting y = 1 in equation ( 3 ), we get,

x = 10 - 7y - - ( 3 )

⇒ x = 10 - 7 * 1

⇒ x = 10 - 7

⇒ x = 3

∴ The solution of the given simultaneous equations is ( x, y ) = ( 3, 1 ).