The mean is calculated by adding up all of the given numbers and dividing by the number of numbers.
Lets, for ease of understanding, say that the first three number were 64...
Mean=(64+64+64)/3=192/3=64
Now, lets solve for the mean where 'x' is the unknown fourth number and 128 is the mean. (since, the answer said that when the fourth number was added the mean, 64, was doubled '64*2=128')
128=(64+64+64+x)/4
128=(192+x)/4
Multiply both sides by 4
512=192+x
subtract 192 from both sides
320=x
The missing number is 320..
Now lets double check our work.
Mean=(64+64+64+320)/4=512/4=128
Answer=320
Answer:
C
15 + x
Step by step explanation
For Company X, the initial cost is 30 cents plus 5 cents per minute, so the expression would be 30 + 5x (x would represent minutes.
For Company Y, the initial cost is 15 cents plus 4 cents per minute, so the expression would be 15 + 4x (x would represent minutes.)
Then subtract the expression of Y from the expression of X to show the difference in value between Y and X.
So, 30 + 5x - (15 +4x)
Distribute the subtraction sign.
30 + 5x - 15 - 4x
Solve across.
15 + x
Answer:
x−3=x−3
Step-by-step explanation:
Evaluate (2x−1)−7, then set it equal to 2.
Subtract 7 from −1 = 2x−8
Solve 2x−8=2.
Move all terms not containing x to the right side of the equation.
Add 8 to both sides of the equation=2x=2+8
Add 2 and 8=2x=10
Divide each term by 2 and simplify.
Divide each term in 2x=10 by 2=2x/2=10/2
Cancel the common factor of 2
Cancel the common factor=10/2
Divide x by 1=x=10/2
Divide 10 by 2=x=5
Remove parentheses=x−3
List all of the solutions.
5=
(2x−1)−7=2=x=5
x−3=x−3
f^3+11g-4hf 3 +11g−4hf, cubed, plus, 11, g, minus, 4, h when f=3f=3f, equals, 3, g=2g=2g, equals, 2 and h=7h=7h, equals, 7.
Alik [6]
Given:
The expression is:
The given values are 
.
To find:
The value of the given expression for the given values.
Solution:
We have,
After substituting , we get
Therefore, the value of the given expression is 21.
Answer:
B and D
Step-by-step explanation:
