Answer:
n(n+1)
Step-by-step explanation:
Only the last two formulas work for n=1; only the last formula works for n=2.
<u>For n=1</u>
3n = 3 ≠ 2
n² -1 = 0 ≠ 2
n² +1 = 2
n(n+1) = 2
<u>For n=2</u>
n²+1 = 5 ≠ 6
n(n+1) = 6 . . . . . this last formula works for the given sequence
1. A
2. C
3. C
4. A
I’m not so sure about number 4 tho!!
Answer:
Not similar -- shape B has been streched, these shapes are neither similar or congruent.
Step-by-step explanation:
Mean is adding all the numbers then dividing the answer you go from the numbers.
Answer:
- <u>120 pens and 200 pencils.</u>
<u></u>
Explanation:
You can set a system of two equations.
<u>1. Variables</u>
<u />
- x: number of pens
- y: number of pencils
<u>2. Cost</u>
- <em>each pen costs</em> $1, then x pens costs: x
- <em>each pencil costs</em> $0.5, then y pencil costs: 0.5y
- Then, the total cost is: x + 0.5y
- The cost of the whole purchase was $ 220, then the first equation is:
x + 0.5y = 220 ↔ equation (1)
<u>3. </u><em><u>There were 80 more pencils than pens</u></em>
Then:
pencils = 80 + pens
↓ ↓
y = 80 + x ↔ equation (2)
<u>4. Solve the system</u>
i) Substitute the equation (2) into the equation (1):
ii) Solve
iii) Substitute x = 120 into the equation (2)
Solution: 120 pens and 200 pencils ← answer
