Lets write the equation
x*1/56= 1/8
Lets do left side
1x/56=1/8
Now we see that in order to remove 56 and only be left with 1x on leftside we have to multipley by 56. If we do so on on side we have to do on the other side. So both sides multiplies by 56
1x/56*56= 1*56/8
From above you see that 1x= 7
x=7
R + b = 146. Supposing that b=r+28,
r + (r+28) = 146, or 2r + 28 = 146.
Simplifying: 2r = 118. Then r = 59, and b = r+28 = 59+28 = 87 blue marbles
Subtract 5x from both sides
0=-30x
Divide both sides by -30
0=x
Final answer: x=0
Hope this helps!
Answer:
7
Step-by-step explanation:
To solve this, we have to work backwards. If you divide something by 9, and it equals 5, to figure out the number, we need to multiply by 9. 5*9= 45. If four was taken away, we have to add it to 45, which is 49. If a number *7 is 49, then we have to divide by 7 to get the answer. 49/7=7
Answer:
51/4
Step-by-step explanation:
To begin with you have to understand what is the distribution of the random variable. If X represents the point where the bus breaks down. That is correct.
X~ Uniform(0,100)
Then the probability mass function is given as follows.

Now, imagine that the D represents the distance from the break down point to the nearest station. Think about this, the first service station is 20 meters away from city A, and the second station is located 70 meters away from city A then the mid point between 20 and 70 is (70+20)/2 = 45 then we can represent D as follows

Now, as we said before X represents the random variable where the bus breaks down, then we form a new random variable
,
is a random variable as well, remember that there is a theorem that says that
![E[Y] = E[D(X)] = \int\limits_{-\infty}^{\infty} D(x) f(x) \,\, dx](https://tex.z-dn.net/?f=E%5BY%5D%20%3D%20E%5BD%28X%29%5D%20%3D%20%5Cint%5Climits_%7B-%5Cinfty%7D%5E%7B%5Cinfty%7D%20D%28x%29%20f%28x%29%20%5C%2C%5C%2C%20dx)
Where
is the probability mass function of X. Using the information of our problem
![E[Y] = \int\limits_{-\infty}^{\infty} D(x)f(x) dx \\= \frac{1}{100} \bigg[ \int\limits_{0}^{20} x dx +\int\limits_{20}^{45} (x-20) dx +\int\limits_{45}^{70} (70-x) dx +\int\limits_{70}^{100} (x-70) dx \bigg]\\= \frac{51}{4} = 12.75](https://tex.z-dn.net/?f=E%5BY%5D%20%3D%20%5Cint%5Climits_%7B-%5Cinfty%7D%5E%7B%5Cinfty%7D%20%20D%28x%29f%28x%29%20dx%20%5C%5C%3D%20%5Cfrac%7B1%7D%7B100%7D%20%5Cbigg%5B%20%5Cint%5Climits_%7B0%7D%5E%7B20%7D%20x%20dx%20%2B%5Cint%5Climits_%7B20%7D%5E%7B45%7D%20%28x-20%29%20dx%20%2B%5Cint%5Climits_%7B45%7D%5E%7B70%7D%20%2870-x%29%20dx%20%2B%5Cint%5Climits_%7B70%7D%5E%7B100%7D%20%28x-70%29%20dx%20%20%5Cbigg%5D%5C%5C%3D%20%5Cfrac%7B51%7D%7B4%7D%20%3D%2012.75)