The average weight of 4 people is 166 pounds. If three of the people weigh 150 pounds, 200 pounds, and 180 pounds. What is the weight of the fourth person?

Step-by-step explanation:

To find the average of 4 things, we add those four things together and divide by 4.  So, here we need to do the opposite.  Since the last thing we would do to find the average is divide by four, we are going to start there and do the opposite.  The average is 166.  So...

166X4=664

Now instead of adding, we will subtract the three that we know, leaving the fourth.  664-200=464    464-150=314      314-180=134

So the weight of the fourth person is 134 pounds.

d, x=8

step-by-step explanation:

simplifying

4x + -5 = 2x + 11

reorder the terms:

-5 + 4x = 2x + 11

reorder the terms:

-5 + 4x = 11 + 2x

solving

-5 + 4x = 11 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-5 + 4x + -2x = 11 + 2x + -2x

combine like terms: 4x + -2x = 2x

-5 + 2x = 11 + 2x + -2x

combine like terms: 2x + -2x = 0

-5 + 2x = 11 + 0

-5 + 2x = 11

add '5' to each side of the equation.

-5 + 5 + 2x = 11 + 5

combine like terms: -5 + 5 = 0

0 + 2x = 11 + 5

2x = 11 + 5

combine like terms: 11 + 5 = 16

2x = 16

divide each side by '2'.