Answer:
x = - 4, x = 5
Step-by-step explanation:
(5x - 25)(x + 4) = 0
Equate each factor to zero and solve for x
x + 4 = 0 ⇒ x = - 4
5x - 25 = 0 ⇒ 5x = 25 ⇒ x = 5
You are given a table in which each row represents the coordinates of points. For example, in the first line, we have x=-7 and y=5. Work through the four given equations, one at a time, subbing -7 for x and 5 for y; is the equation still true? If yes, then you have found the correct answer. B is the exception; I'd suggest you check out equations A, C and D first, before focusing on B.
Example: D: (5)-5 = 2((-7) + 7) leads to 0 = 0. Is that true? If so, D is likely the correct answer.
The equation would be 30+3m=162 then you solve the problem
We need the half-life of C-14 which is 5,730 years.
Now, we will need a half-life equation:
elapsed time = half-life * log (bgng amt / ending amt) / log 2
We'll say beginning amount = 100 and ending amount = 41
elapsed time = 5,730 * log (100/41) / log 2
elapsed time = 5,730 * log (
<span>
<span>
<span>
2.4390243902
</span>
</span>
</span>
) / 0.30102999566
elapsed time = 5,730 * 0.38721614327 / 0.30102999566
elapsed time =
<span>
<span>
</span></span><span><span><span>5,730 * 1.2863041851
</span>
</span>
</span>
<span>elapsed time = 7,370.523 years
Source:
http://www.1728.org/halflife.htm </span>
