Step-by-step explanation:
Sn=n/2(2a+(n-1)d)
910=n/2{2a+(n-1)d}
1820=n{2a+(n-1)d}
1820=20{2a+(20-1)d}
1820=20{2a+19d}
91=2a+19d
An=a+(n-1)d
95=a+(20-1)d
95=a+19d
91=2a+19d
---------------
4=-a
a=-4
91=2a+19d
91=2(-4)+19d
91=-8+19d
91+8=19d
99=19d
d=99/19
A=-4
2.645751311 (I did it on a scientific calculator, so sorry if they wanted you to show the work..)
Answer:
92
Step-by-step explanation:
Given
2n + t² ← substitute n = - 4 and t = - 10 into the expression
= 2(- 4) + (- 10)² = - 8 + 100 = 92
Answer:

Step-by-step explanation:
Step 1: Define
Difference Quotient: 
f(x) = -x² - 3x + 1
f(x + h) means that x = (x + h)
f(x) is just the normal function
Step 2: Find difference quotient
- <u>Substitute:</u>
![\frac{[-(x+h)^2-3(x+h)+1]-(-x^2-3x+1)}{h}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B-%28x%2Bh%29%5E2-3%28x%2Bh%29%2B1%5D-%28-x%5E2-3x%2B1%29%7D%7Bh%7D)
- <u>Expand and Distribute:</u>
![\frac{[-(x^2+2hx+h^2)-3x-3h+1]+x^2+3x-1}{h}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B-%28x%5E2%2B2hx%2Bh%5E2%29-3x-3h%2B1%5D%2Bx%5E2%2B3x-1%7D%7Bh%7D)
- <u>Distribute:</u>

- <u>Combine like terms:</u>

- <u>Factor out </u><em><u>h</u></em><u>:</u>

- <u>Simplify:</u>

Answer:
$1,065,597.22
Step-by-step explanation:
Simple interest = Principal * Rate * Time/100
10,510 = P * 12 * 30/365*100
10,510*365*100 = 360P
383,615,000 = 360P
Note that the time was converted to years by dividing by 365
P = 383,615,000/360
P = $1,065,597.22
Hence the principal is $1,065,597.22