Answer:
the mean =19.5
Step-by-step explanation:
Answer:
x = -12
Step-by-step explanation:
-2.5(x-4)=-3x+4
Distribute
-2.5x +10 = -3x +4
Add 3x to each side
-2.5x+10 +3x = -3x+4+3x
.5x +10 = 4
Subtract 10 from each side
.5x+10-10=4-10
.5x = -6
Divide by .5
.5x/.5 = -6/.5
x = -12
The sum of n terms of a geometric sequence with first term "a" and common ratio "r" is given by

You have a=21, r=3, so the sum of 10 terms is

The appropriate choice is the 2nd one:
620,004
9, 9(2)=18, 9(3)=27, 9(4)=36 9(5)=45
9,18,27,36,45……..144
Not sure if this is what you are looking for. If the number of blanks is the amount of numbers allowed then the above will not work
9(13)=117, 9(14)=126, 9(15)= 135, 144
If you can only have 3 blanks then the second one could work.
Again, not sure if this is what you need. But hopefully it helps.