Rust compiler errors

rustc

   |
13 |     let x, y = 21, 22;
   |         -^-- help: try adding parentheses: `(x, y)`
----
   |
24 |     println!("val {:?} {:?} {:?}", pt, pt2, pt3);
   |                                    ^^ did you mean `pt1`?
----
error[E0499]: cannot borrow `vec` as mutable more than once at a time
 --> src/main.rs:5:9
  |
4 |     for n in &mut vec {
  |              --------
  |              |
  |              first mutable borrow occurs here
  |              first borrow used here, in later iteration of loop
5 |         vec.push(*n * 10);
  |         ^^^ second mutable borrow occurs here
----