Question

How do you find the coordinates of the point of intersection for the pair of lines whose equations y=2x-1 and x+2y=8?

Answer 1

`x = 2 and y = 3`

Explanation:

`y = 2x - 1` . . . .(1)
`x + 2y = 8` . . . . (2)
(1) * 2 = 2y = 4x - 2 . . . .(3)
(2) - (3) = x = 8 - 4x + 2
i.e., `4x + x = 5x = 8 + 2 = 10`
or `x = 10 / 5 = 2`
`y = 2 * 2 - 1 = 3`

Answer 2

I found:
`x=2`
`y=3`

Explanation:

You can use the value of `y` from the first equation and substitute into the second to get:
`x+2(color(red)(2x-1))=8` and solve for `x`:
`x+4x-2=8`
`5x=10`
`x=10/5=2`
use this value back into the first equation to find `y`:
`y=2*2-1=4-1=3`