Answer:
one, no, one, infinitely
Step-by-step explanation:
a. you can get 7x = 21 - 21 = 0 ==> x = 0
b. subtract 12x from both sides ==> get 15 = -15, which is not true
c. -5x-5x=25+25 ==> -10x = 50 ==> x = -5
d. get -2x -6 -7 = -2x - 6 - 7 ==> so it's infinitely
18
we start to write a few iterations of 6 and 9:
6, 12, 18, 24, 30, 36, 42, 48, 54, 60, ...
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, ...
the LCD is the least repeating number in both sequences. It is 18
the effect size index is =0.7437
2 is the absolute mean deviation
absolute mean deviation is
the average of the differences of the data from the average
8, 8, 4, 12
1. take the average
8+8+4+12=32 -> 32/4 = 8
2. subtract each number from this average
8 - 8 = 0
4 - 8 = 4 (there are no negative answers)
12 - 8 = 4
3. take the average of these subtractions
0+0+4+4=8 -> 8/4 = 2
4. answer: 2 is the absolute mean deviation
About $9.65.
Cost divided by quantity.
