After 2.0 years, the 4.0 mg sample decays to 2.0 mg.
After another 2.0 years (total 4.0 years), the 2.0 mg sample decays to 1.0 mg.
And after another 2.0 years (total 6.0 years), the 1.0 mg sample decays to 0.50 mg.
So it takes 6.0 years for 4.0 mg to decay to 0.50 mg.
0,3 3,3 2,3 and 1,2 (from A to D)
Answer: G
Explanation/Calculation:
You can clearly see that the white shapes are positive while the black shapes are negative. You can determine this because all (except F) claim that the 6 shapes are negative.
To make it easier, use elimination. It's definitely not J because you are not subtracting -6, but adding (as seen in the equation.) It is not F because 2(3)=6 when the equation needs -6.
So it is either G or H...
H claims that 12x+3+(-6) is what the model symbolizes; but this is incorrect. Unless x is a decimal, you can not have the large shape as the "purest" form (so to speak.) The "purest" state you can go in this model is a cube/square which=1.
Therefore, "G Jamey modeled 12 + 3x + (-6) and it is equivalent to 12x-3" is the correct answer.
Hope this helps you!
4/15 is it's lowest terms. 2 is the lowest number that goes into both 8 and 30. It goes into 8 four times, and 30 15 times.
~Silver
