the sum of the first 6 terms of a geometric series is 15624 and the common ratio is 5. what is the first term of the series?

Mathematics

1 answer:

9966 [12]2 years ago

7 0

Answer:

first term a=4

Step-by-step explanation:

Sum of the first 6 terms S6 = 15624

common ratio r= 5

n= 6

first term a=?

Formula: S6= a(r^n-1)/r-1

15624 = a( 5^6-1)/5-1

15624 = a(15625-1)/4

15624= a( 15624)÷4

15624= 15624a÷4

Cross multiply

15624×4 = 15624a

62496 = 15624a

divide both sides by 15624

62496÷15624 = 15624a÷15624

4 = a

a= 4

You might be interested in

Question 2

Free_Kalibri [48]

I’m terms of 12 in is the correct answer.

7 0

1 year ago

For each hour he babysits, Anderson earns $1 more than half of Carey’s hourly rate. Anderson earns $6 per hour. Which equation c

ozzi

Carey earns c hourly
Anderson earns $6 hourly which is also 1+ c/2
So, 6=1+c/2
12=2+c
c=$10
Carey earns $10 hourly

3 0

2 years ago

Read 2 more answers

2b=6a-14,3a-b=7 how to work it out

pshichka [43]

So, since there are two equations, we can substitute one of them into the other. In this case, it would be easiest to substitute 2b=6a-14 into the other equations. But first, simplify by dividing both sides by 2. You bet b=3a-1

We can now plug this into the other equation
Sine the equation b=3a-1 results in the value of b, we have to plug in for the value of b in the other equation

So this is what we get after plugging in:
3a-(3a-1)=7
Now, simplify. 3a-3a+1=7
Since 3a-3a = 0, this equation results in a no solution

Answer:
The result is a no-solution, or Ф

Hope this helped!! :D

5 0

2 years ago

Read 2 more answers

Bao is mixing flour and water to make dough. The graph shows how much water he uses for different amounts of flour.

Butoxors [25]

Answer:

0.33 liters of water Bao use per liter of flour.

3 liters of flour Bao use per liter of water

Step-by-step explanation:

Given the graph which pass through the coordinates (0,0) and (3,1)

∴ Equation of line passing through these points can be written as

$(y-y')=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}(x-x')$