calling variable that holds a previous output.

Questions
1

I have a equation system with two variables. And the Mathematica gives a solution.

How can I call this solution a line down to do another calc.

This question is for automatization process I’m doing.

Solve[x + y == 2 && x - y == 1, {x, y}]
{{x → 3/2, y → 1/2}}

2

(* Original equation *)
sol = Solve[x + y == 2 && x - y == 1, {x, y}]

(* Use solution for another function of x and y *)
x + 7 y /. Flatten[sol]
3

This is how I save it

sol = Solve[x + y == 2 && x - y == 1, {x, y}];
x = x /. Flatten[sol]
y = y /. Flatten[sol]

It says is an error

4

You’re missing a semicolon

sol = Solve[x + y == 2 && x - y == 1, {x, y}]; x = x /. Flatten[sol]; y = y /. Flatten[sol]

Undo the symbol damage with Clear["x"];Clear["y"];
Re-execute and your answers will be OK.