If you have 1 nickle, how many quarters do you have? (3)
If you have 4 nickles, you have 3 times as many quarters (3)(4) = 12
If you have n nickles, then you have 3n quarters so 3n = q, you have a slightly different equation.
If you fix this equation and use substitution like you did, you can get the right answer; you can also try to work in the other information that you have - converting all coin values to cents
5n + 10d + 25q = 460
The vertex is the center point of the line or the axis of symmetry
So your answer should be (-2, -5)
0.7 miles
Explanation:
42/60 = 0.7
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 !
