Answer:
p=-6
q=3
Step-by-step explanation:
5p-3q=-39
-2p-3q=3
Multiply the second equation by -1
2p +3q = -3
Add the first equation and the modified second equation
5p-3q=-39
2p +3q = -3
---------------------
7p = -42
Divide by 7
7p/7 = -42/7
p = -6
Now we can find q
2p +3q = -3
2(-6) +3q = -3
-12 +3q = -3
Add 12 to each side
-12+12 +3q = -3+12
3q = 9
Divide by 3
3q/3 = 9/3
q=3
Answer:
yes :)
Step-by-step explanation:
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 !
