To solve the equation \(0.00000000013284=13284\times10^{-x}\), we must realize that we are trying to get the same base. First, convert \(0.00000000013284\) into a scientific form.
To do this, move the decimal point of \(0.00000000013284\) such that the decimal point moves in front of the first nonzero digit of the number. The number of times one moves is what the 10 will be raised to. Knowing this, \(0.00000000013284=1.3284\times10^{-10}\). We have now changed the equation to the following:
\(1.3284\times10^{-10}=13284\times10^{-x}\)
Now, let's continue moving that decimal of 1.3284 to the right. We'll move it 4 decimal places. This means that \(1.3284\times10^{-10}=13284\times10^{-14}\). Oh look! we have the same base now. Let's solve for x:
\(13284\times10^{-14}=13284\times10^{-x}\) | Divide by 13284 on both sides. |
\(10^{-14}=10^{-x}\) | Our goal is to make the exponents the same. With this equation, the following is implied. |
\(-14=-x\) | Divide by -1 on both sides. |
\(x=14\) | |
And there you go!
I'm assuming that we are solving for v in the equation \(v^2=\frac{25}{81}\). Let's do that!
\(v^2=\frac{25}{81}\) | Take the square root of both sides to isolate v. Of course, the square root always results in 2 answers: The positive and negative. |
\(v=\pm\sqrt{\frac{25}{81}}\) | "Distribute" the square to both the numerator and denominator. |
\(v=\pm\frac{\sqrt{25}}{\sqrt{81}}\) | Now, simplify both the numerator and denominator. |
\(v=\pm\frac{5}{9}=\pm0.\overline{55}\) | |
a) We have three standard 6-sided dice, colored red, yellow, and green. In how many ways can we roll them to get a sum of 9? The dice are colored so that a red 2, yellow 3, and green 4 is a different roll from red 3, yellow 4, and green 2.
These numbers are small enough so I can just count them
Green | number left | Y/R | Y/R
| Number of combination |
1 | 8 | 2 | 6 | 2 |
1 | 3 | 5 | 2 | |
1 | 4 | 4 | 1 | |
2 | 7 | 1 | 6 | 2 |
2 | 5 | 2 | ||
3 | 4 | 2 | ||
3 | 6 | 1 | 5 | 2 |
2 | 4 | 2 | ||
3 | 3 | 1 | ||
4 | 5 | 1 | 4 | 2 |
2 | 3 | 2 | ||
5 | 4 | 1 | 3 | 2 |
2 | 2 | 1 | ||
6 | 3 | 1 | 2 | 2 |
TOTAL | 25 |
(b) We have 10 standard 6-sided dice, all different colors. In how many ways can we roll them to get a sum of 20?
Yea you can think about this one by thinking of the logic that happened with my first one.
I might think on it later. :)