# Algebra

I have a few problems I need some help with.

The first is Evaluate the sum.
1. There is an E like symbol on the top is 10 on the bottom n=1 and to the right (7-2n)

2. The next question is find a10 for an arithmetic sequence with a1=6 and d=10

3. Find the number of terms in the series and then find the sum. Evaluate the sum.
16+23+30+37+44+.....+93

1. 0
2. 0
3. 18
1. 1. What you have is an arithmetic sequence where a=3 and d=-2
So, S10, the sum of the first 10 terms, is

S10 = 10/2 (2*3 + 9(-2)) = -60

same way for #2

3. looking at the terms, the difference is 7. Dividing the range of terms, we see that (93-16)/7 = 11

So, 7 is added to 16 11 times to get to 93. So, there are 12 terms.
Now find the sum the same way, using a=16,d=7,n=12

1. 0
2. 0
posted by Steve

## Similar Questions

1. ### Algebra

Here is the problem: A two-digit number is eight times the sum of its digits.When the number is added to the number obtained by reversing the digits,the sum is 99. Find the original number. Please explain hot to solve it and it

2. ### Algebra

Here is the problem: A two-digit number is eight times the sum of its digits.When the number is added to the number obtained by reversing the digits,the sum is 99. Find the original number. Please explain hot to solve it and it

asked by Anonymous on May 31, 2010
3. ### calculus1

Hi, I have 3 problems here need to be solved, help me please 1.Evaluate ∫ sin2x sec^5(2x)dx 2. If f(x)=√x and P is a partition of [1,16] determined by 1,3,5,7,9,16,find a Riemann sum Rp of f by choosing the numbers 1,4,5,9 and

asked by karen on June 10, 2015
4. ### 4th Grade Math: Help Is Needed ASAP

My son is in the fourth grade and is needing help with these math problems. Can someone please help him with these problems. 1. 2/3+2/9= 2. 3/5+3/10= 3. 5/12+1/3= 4. Find the sum of 1/6 and 1/12 5. Add 1/4 to the answer in

asked by Tim on November 19, 2013
5. ### math

find thedomain and range of {(7,-2), (-6,-4) (9-9,)-(5-5)}= evaluate f(x) +3x^2-4x-3at f(x-1)= evaluate f(x)= -5x+8 atf(-3)= it will be well appreciated of what how and help with these math problems plz thank you

asked by sherri on January 4, 2009
6. ### Math. Need help

1.if g=5 and k=1, evaluate 9+gk a. 13 b. 14 c. 15 d. 16 2.Evaluate a-b^2/b if a = 10 and b = 2. a. 1 b. 3 c. 8 d. 32 3.Evaluate 3xy^2 - y if x = 2 and y = 5. a. 26 b. 30 c. 120 d. 145 4.Evaluate 2d + d^2/3 if d = 6. a. 4 b. 12 c.

asked by A. on August 29, 2016
7. ### Calculus

Evaluate using the sum of a finite geometric series: The sum of 2^i on the range from i = 1 to n. Please Help! I don't know how to make the exponent in 2^i = to i-1!

asked by Marie on January 10, 2015
8. ### Calculus

I am having trouble with these 2 problems. Evaluate: (1/x^9)dx Evaluate: (5x^5-4x^3+6x)dx

asked by Josh on August 26, 2011