Answer:

Step-by-step explanation:
-5+2(10b-2)=31
Expand brackets.
-5+20b-4=31
-9+20b=31
Add 9 on both sides.
20b=40
Divide both sides by 20
b=2
I think you mean circumference, which is equal to = 2πr
939/10,000 the decimal place indicates the fraction. You would love the decimal over 4 spaces which is the ten thousands place so that is what you set 939 over!
Answer:
n>3
Step-by-step explanation:
Step 1: Add 1 to both sides.
3n−1+1>8+1
3n>9
Step 2: Divide both sides by 3.
3n/3>9/3
n>3
Answer:
27) 14x
28) n/9
29) A number, z, divided by 11
30) The sum of a number, z, and 11