Answer:
None of the above
Step-by-step explanation:
There is no number that appears twice or thrice
Answer:
f = 
Step-by-step explanation:
Given
b = fjn ( isolate f by dividing both sides by jn )
= f
8a + a - 3 = 6a - 2a - 3
1. Add the a's on both sides:
9a - 3 = 4a - 3
2. Shift 4a to the left and -3 to the right of the equals sign (this changes their signs):
9a - 4a = -3 + 3
3. Simplify:
5a = 0
So a = 0
Answer:

Step-by-step explanation:

To solve this problem you must apply the following proccedure:
1. You have a total of 21 coins, all nickels and dimes. Then:
x:nickels=5 cents
y: dimes=10 cents
x+y=21
2. You have that the total value is $1.70. Then:
5x+10y=170
3. The system of equation is:
x+y=21 (i)
5x+10y=170 (ii)
4. You have:
x+y=21
x=21-y
5(21-y)+10y=170
105-5y+10y=170
y=13 dimes
x+13=21
x=8 nickels