Question

Solve:
x + y = 7
3x - 2y = 11

By using Substituting method.​

Answer 1

`\large\underline{\sf{Solution-}}`

`\sf \longmapsto x + y = 7 \: \: - - - (i)`

`\sf \longmapsto 3x - 2y = 11 \: \: - - - (ii)`

By first equation,

`\sf \longmapsto x + y = 7`

`\sf \longmapsto x = 7 - y`

Now, we can find the original value of y.

`\sf \longmapsto 3x - 2y = 11`

`\sf \longmapsto 3(7 - y) - 2y = 11`

`\sf \longmapsto 21 - 3y - 2y = 11`

`\sf \longmapsto 21 - 5y = 11`

`\sf \longmapsto - 5y = 11 - 21`

`\sf \longmapsto - 5y = - 10`

`\sf \longmapsto y = ( - 10)/( - 5)`

`\sf \longmapsto y = 2`

Now, we can find the original value of x.

`\sf \longmapsto x + y = 7`

`\sf \longmapsto x + 2 = 7`

`\sf \longmapsto x = 7 - 2`

`\sf \longmapsto x = 5`

Therefore, the values of x and y are 5 and 2 respectively.