How does this work?

```
julia> r = [1, 2]
2-element Array{Int64,1}:
1
2
julia> [1 2; 3 4]
2×2 Array{Int64,2}:
1 2
3 4
julia> r \ [1 2; 3 4]
1×2 Array{Float64,2}:
1.4 2.0
```

If A is a rectangular m-by-n matrix with m ~= n, and B is a matrix with m rows, then A\B returns a least-squares solution to the system of equations A*x= B, or

If A is a scalar, then A\B is equivalent to A.\B?

I couldn’t figure out if what was stated in `?\`

meant the same thing, I don’t think it did. Thanks!