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
3. 5mn ( 2m + 6n + 1 )
4. 4a^3b^2c ( 18a^2b - 8c )
5. (X-15)(X+15)
6. -4(y-4.5)(y+4.5)
8. 2X(X-10)(X+10)
i am not sure if no. 8 is right
Answer:
x = -13,67
Step-by-step explanation:
-3x - 5 = 36
-3x = 36 + 5
-3x = 41
x = 41/-3
x = -13 2/3
or
x = -13,67
make as the brainliest
I am not sure is you are supposed to solve or rewrite but for solving its this picture, tell me if its rewriting the problem and ill give you that as well!