Solue it be simultaneousequations 2x+y=8 ; x-2y=-1​

x = 3

y = 2

2x + y = 8 ------> 1.

x - 2y = - 1

x = - 1 + 2y ------> 2.

Substitute 2 in 1,

2 ( - 1 + 2y ) + y = 8

- 2 + 4y + y = 8

- 2 + 5y = 8

5y = 8 + 2

5y = 10

y = 10 / 5

y = 2

Substitute y = 2 in 2.

x = - 1 + 2 ( 2 )

= - 1 + 4

x = 3