Find the value of x.
31.7, 42.8, 26.4, x, mean 35

x = 39.1

Step-by-step explanation:

mean = average off all the numbers =

sum of the numbers / amount of numbers.

35 = sum of the #'s / # of #'s

35 = 100.9 + x / 4

35 × 4 = 100.9 + x / 4 × 4

140 = 100.9 + x

140 – 100.9 = 100.9 + x – 100.9

39.1 = x

x = 39.1

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,