Answer:
4x + 6
Step-by-step explanation:
If i remember correctly, two minuses make a positive, so -(-6) would turn into +6. I dont think that you can add a number with a variable to a regualar number so the answer is as simplified as it can get. If that one is wrong, try 10x. Hope this helps!
The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
Do you have a picture to go with it?
