12.5%, every 500 years you take away half of the substance (50%) -> 25% -> 12.5%
you divide your number 3 times because 1500/500=3
Answer:
C
1/3y - 7/5×+ 2/3-2/3 y- 4/9
The first and second ones
Answer:
y=2^x
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
The velocity of a moving body is given by the equation:

Is the velocity is <em>positive </em>(v>0), then our object will be moving <em>forwards</em>.
And if the velocity is negative (v<0), then our object will be moving <em>backwards</em>.
We want to find between which interval(s) is the object moving backwards. Hence, the second condition. Therefore:

By substitution:

Solve. To do so, we can first solve for <em>t</em> and then test values. By factoring:

Zero Product Property:

Now, by testing values for t<1, 1<t<4, and t>4, we see that:

So, the (only) interval for which <em>v</em> is <0 is the second interval: 1<t<4.
Hence, our answer is A.