I'll do problem 13 to get you started.
The expression
is the same as 
Then we can do a bit of algebra like so to change that n into n-1

This is so we can get the expression in a(r)^(n-1) form
- a = 8/7 is the first term of the geometric sequence
- r = 2/7 is the common ratio
Note that -1 < 2/7 < 1, which satisfies the condition that -1 < r < 1. This means the infinite sum converges to some single finite value (rather than diverge to positive or negative infinity).
We'll plug those a and r values into the infinite geometric sum formula below
S = a/(1-r)
S = (8/7)/(1 - 2/7)
S = (8/7)/(5/7)
S = (8/7)*(7/5)
S = 8/5
S = 1.6
------------------------
Answer in fraction form = 8/5
Answer in decimal form = 1.6
Step-by-step explanation:
slope of the given line=2/3
since the required line is parallel to the given line, it's slope will be same.
hence slope of required line:2/3
The required line passes through the point(9,1),
hence the equation of the required line,
y-1=(2/3)(x-9)
3y-3=2x-18
2x-3y-15=0
There the equation of the required line is 2x-3y-15=0
Answer:
$6
Step-by-step explanation:
she has $8 now
her parents let her earn $5
so you have to take the $5 from the $8
so $8 - $5 = 3
and she had spent half her allowance so you have to double the $3
$3 * 2 = $6
she has a weekly allowance of $6
Answer:
10x - 15
Step-by-step explanation:
let Emily's be x hrs
Abbey = 3x-5 hrs
Nathan = 2 * Abbey's time= 2(3x-5)
= 6x-10 hrs
Expression= x + 3x-5 + 6x-10 = 10x - 15 hrs
Therefore, 10x - 15 is the EXPRESSION THAT DENOTES THE TOTAL NUMBER OF HOURS SPENT FOR DOING HOMEWORK COLLECTIVELY.