Answer: -10 and 68
Step-by-step explanation:
We have the numbers, ordered from least to greatest:
11, 26, 29, 31, 43, 44, 47 and x.
The range is equal to the difference between the largest number and the smallest number, so, x can take two values.
The smallest number:
here we have that:
47 - x = 57
x = 47 - 57 = -10
The other possibility is that x is the largest number, in this case, we have that:
x - 11 = 57
x = 57 + 11 = 68.
Then the two possibla values of x are -10 and 68
