The only things you can factor out of here is a 3 so you are left with:
3(y-6)
Hope that helps.
Step-by-step explanation:
Mean of the origibal set = 20
No. of terms = 10
Sum = Mean x No. of terms
= 20 x 10 = 200
The sum of additional numbers to make the new set of observstion is 4 + 8 + 12...... + 40 = 220
New Sum = 200 + 220 = 420
The no of terms stay the same
New Mean = New Sum/ N
= 420/10
= 42
One is going 52 and the other 64
2 (x)+2 (x+12)=232 and solve
is the answer for this question -4 + 8x