Question

If `2x-7/2+3/2y` and `4x+3y=7`, what are `x` and `y`?

Answer 1

Provided I have correctly interpreted what was intended:
`color(white)("XXX")(x,y)=(7/4,0)`

Explanation:

Note that in order for the first expression to be an equation, I have replaced the `color(blue)+` in `2x-7/2color(blue)+ -3/2y` with an `color(red)(=)`. (I assumed this was a typo and the `color(blue)+` and the `color(red)=` are typically on the same key).

Given
[1]`color(white)("XXX")2x-7/2color(red)(=)3/2y`
[2]`color(white)("XXX")4x+3y=7`

Rearranging [1] into standard form (`Ax+By=C, ABC in ZZ`)
[3]`color(white)("XXX")4x-3y=7`

Adding [2] and [3] together
[4]`color(white)("XXX")8x=14`
`rArr`[5]`color(white)("XXX")x=7/4`

Subtracting [3] from [2]
[6]`color(white)("XXX")6y=0`
`rArr`[7]`color(white)("XXX")y=0`