Answer:
<h3>
a. a₁=7, b. a_n=7n+1, c. a₂₀=141</h3>
Step-by-step explanation:
a.
![a_1=S_1=3\cdot1^2+4\cdot1=3+4=7](https://tex.z-dn.net/?f=a_1%3DS_1%3D3%5Ccdot1%5E2%2B4%5Ccdot1%3D3%2B4%3D7)
b.
![a_1+a_2=S_2\\\\a_1+a_1+d=3\cdot2^2+4\cdot2\\\\7+7+d=3\cdot4+8\\\\14+d=12+8\\\\d=6\\\\\\a_n=a_1+d(n-1)\\\\a_n=7+6(n-1)\\\\a_n=7+6n-6\\\\\underline{a_n=7n+1}](https://tex.z-dn.net/?f=a_1%2Ba_2%3DS_2%5C%5C%5C%5Ca_1%2Ba_1%2Bd%3D3%5Ccdot2%5E2%2B4%5Ccdot2%5C%5C%5C%5C7%2B7%2Bd%3D3%5Ccdot4%2B8%5C%5C%5C%5C14%2Bd%3D12%2B8%5C%5C%5C%5Cd%3D6%5C%5C%5C%5C%5C%5Ca_n%3Da_1%2Bd%28n-1%29%5C%5C%5C%5Ca_n%3D7%2B6%28n-1%29%5C%5C%5C%5Ca_n%3D7%2B6n-6%5C%5C%5C%5C%5Cunderline%7Ba_n%3D7n%2B1%7D)
c.
![a_{20}=7\cdot20+1=141](https://tex.z-dn.net/?f=a_%7B20%7D%3D7%5Ccdot20%2B1%3D141)
Answer:
Step-by-step explanation:
<u>You need to find the difference:</u>
- 17.50x + 25 - (8.50x + 3) =
- 17.50x - 8.50x + 25 - 3 =
- 9x + 22
Correct one is B
Answer:5
Step-by-step explanation:
Answer: 0.8% of 5,700 = <u><em>45.6 </em></u>
Step-by-step explanation:
0.8% × 5,700 =
(0.8 ÷ 100) × 5,700 =
(0.8 × 5,700) ÷ 100 =
4,560 ÷ 100 =
45.6;
900x300=270,000 plus 2 would equal 270,002.4 devided by 3-2001 would equal 87,999.8