40x - 24 - 33x - 77 = 102
40x - 33x = 102 + 24 + 77
7x = 203
x = 29
Answer:

Step-by-step explanation:
Given

Required
Determine an equivalent expression
Express 81 as 

Apply law of indices






Hence:

The answer would be <em>29.5562243957</em>.
Answer:

Step-by-step explanation:
Hello,
<u>The mean of five numbers is 8</u> so we can write

<u>When another number is added the mean is 7</u>, let s note x the another number we can write

From the first equation we can say

So the second equation becomes

The solution is then 2
Hope this helps