Can you solve this picture maths equation?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

What has 13 hearts but no other organs?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

What do the following words have in common?

Assess
Banana
Dresser
Grammar
Potato
Revive
Uneven
Voodoo

Can you replace the question mark with the correct number?

What is the word or phrase below?
R | E | A | D

Can you find out which number multiplied by itself will give the output as 12345678987654321?