That is exactly 8 half lives.
After 8 half - lives only (1 / 2^8) or (1 / 256) of the original 30 grams will remain.
(1 / 256) =
<span>
<span>
<span>
0.003906250
</span>
</span>
</span>
So, 30 * <span>
<span>
0.003906250 = </span></span>
<span>
<span>
<span>
0.1171875 grams will remain.
</span></span></span>
<span>Multiply one of the equations so that both equations share a common complementary coefficient.
In order to solve using the elimination method, you need to have a matching coefficient that will cancel out a variable when you add the equations together. For the 2 equations given, you have a huge number of choices. I'll just mention a few of them.
You can multiply the 1st equation by -2/5 to allow cancelling the a term.
You can multiply the 1st equation by 5/3 to allow cancelling the b term.
You can multiply the 2nd equation by -2.5 to allow cancelling the a term.
You can multiply the 2nd equation by 3/5 to allow cancelling the b term.
You can even multiply both equations.
For instance, multiply the 1st equation by 5 and the second by 3. And in fact, let's do that.
5a + 3b = –9
2a – 5b = –16
5*(5a + 3b = -9) = 25a + 15b = -45
3*(2a - 5b = -16) = 6a - 15b = -48
Then add the equations
25a + 15b = -45
6a - 15b = -48
=
31a = -93
a = -3
And then plug in the discovered value of a into one of the original equations and solve for b.</span>
Answer:
25
Step-by-step explanation:
<h3>Hello!</h3>

Negative numbers are always less than positive ones.
Do you remember the symbol for "less than"? That's right, "<" :)
Hence,
-6<3
Because
-6 is negative (the - sign tells us that)
3 is positive

<h3>Notes:</h3>
- Hope everything is clear.
- Let me know if you have any questions!
<h3>Answered by:</h3>
~DiamondS~