Answer:
-5n + 8
Step-by-step explanation:
<u>1. What is the difference?</u>
The sequence goes down by 5. This means that the formula will have -5n in it.
<u>2. Work out the term before the first term.</u>
The first term is 3, and we know that the sequence goes up by 5. So, to get the term before 3 we would add 5.
3 + 5 = 8 Remember, this is positive 8. (+8)
<u>3. Put that term at the end of the equation. </u>
We have -5n already and we just worked out the term before the first one which is positive 8 - so put that at the end of the equation.
-5n + 8 This is our answer!
Just to prove it works:
<em>Substitute: n = term</em>
Lets see if we can get the 3rd term which is -7. (n = 3)
-5(3) + 8
-15 + 8 = -7
See, it works!
The primes are 2, 3, 5, 7, 11, 13, 17, 19. There are 8 of them, so they make up 40% of the numbers 1–20.
3(x-5)=1+(5x+2x)
3x-15=1+7x
-15=1+7x-3x
-15=1+4x
-15-1=1+4x-1
-16=4x
-16/4=4x/4
-4=x
Answer:
-2/3 gallon/minute
Step-by-step explanation:
In three minutes the water volume has decreased by 2 gallons (7 less 5 is 2). The unit rate of decrease of the amount of water in the tank is thus:
- 2 gallons
------------------- = -2/3 gallon/minute
3 minutes