Give me a source. If it equals, it's the same. It won't change the outcame of any equation, never will. You are truly retarded. I should probably just give up arguing with you, and when you return to school after the summer break to your 6th grade in elementary school, your teacher can explain it to you.
You aren't ignoring rules, you are making them up.
If there's no * before a bracket, then it's just invisible, but it is still there and nothing changes.