Use the Counting Principle to find the probability of rolling a 5 on each of 2 number cubes.

lorasvet [3.4K]

Answer: $x = \frac{mn(q - p)}{n-m}\\\\$

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Work Shown:

Part 1

$\frac{x-m}{m} + p = \frac{x-n}{n} + q\\\\\frac{x-m}{m} - \frac{x-n}{n} = q - p\\\\\frac{n(x-m)}{mn} - \frac{m(x-n)}{mn} = q - p\\\\\frac{xn-mn}{mn} - \frac{xm-mn}{mn} = q - p\\\\\frac{xn-mn-(xm-mn)}{mn} = q - p\\\\$

Part 2

$\frac{xn-mn-xm+mn}{mn} = q - p\\\\\frac{xn-xm}{mn} = q - p\\\\\frac{x(n-m)}{mn} = q - p\\\\x(n-m) = mn(q - p)\\\\x = \frac{mn(q - p)}{n-m} \\\\$

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Explanations:

There are quite a bit of steps. I decided to break things into two parts.
The goal is to get x all by itself on its own side, which is why I subtracted (x-n)/n from both sides in part 1, step 2. I also subtracted p from both sides.
Afterward, I gave each fraction the LCD mn. I multiplied top and bottom of the first fraction by n/n. I did a similar operation to the second fraction, but with m instead.
From there, we distribute and simplify. The mn terms cancel on the left side numerator (second step of part 2).
The n≠m is there to prevent the denominator (n-m) from being zero. We cannot divide by zero.
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7 0

3 years ago

What is 3x +99 2(8*3)= 135<br> what is x equal to?

Ivenika [448]

Answer: -4

Step-by-step explanation: I am guessing you meant ...99 + 2(8*3)...

3x + 99 + 2(8 x 3) = 135

3x + 99 + 2(24) = 135

3x + 99 +48 = 135

3x + 147 = 135

(3x + 147) - 147 = (135) - 147

3x = -12