3x +4x + 6 -x➋ - 3× -3
formula
online, we usually use * for multiplication, to avoid confusing x with a variable.
Also, x^2 for "x squared"
That said, I have no idea what you mean, asking for the "formula."
3x+4x = 7x
3 * -3 = -9
not sure just what it is you want to do with that somewhat garbled algebraic expression.