Answer: 
Step-by-step explanation:
I hope you mean y = x² - 12 and not y = 2x - 12.
You switch the y and x variables:
x = y² - 12
And solve for y:
x + 12 = y²

The mass is 15 and can you speak english.
Answer:
natural # - the positive integers (whole numbers) 1, 2, 3, etc., and sometimes zero as well.
whole # & integer -numbers w no fractions
Step-by-step explanation: