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zheka24 [161]
3 years ago
11

What is the sum of the first five terms of a geometric series with a1 =20 and r =1/4?

Mathematics
1 answer:
drek231 [11]3 years ago
5 0
The sum of the first n terms in a geometric sequence given the first term (a1) and the common ratio (r) is calculated through the equation,

                            <span>Sn </span>= (<span><span><span>a1</span>(1−<span>r^n</span>) / (</span><span>1−r)

Substituting the known terms,
                           Sn = (20)(1 - (1/4)^4)) / (1 - 1/4)
                           Sn = 26.5625

Thus, the sum of the first four terms is 26.5625. </span></span>
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Given that f(x)=x^2+3x+6 and g(x)= x-3/2, solve for f(g(x)) when x=1
podryga [215]
If you would like to solve for f(g(x)) when x = 1, you can do this using the following steps:

<span>f(x) = x^2 - 3x + 6
g(x) = x - 3/2

f(g(x)) = f(</span>x - 3/2) = (x - 3/2)^2 - 3 * (x - 3/2) + 6
x = 1
f(g(1)) = f(1 - 3/2)  = f(-1/2) = (-1/2)^2 - 3 * (-1/2) + 6 = 1/4 + 3/2 + 6 = 1/4 + 6/4 + 24/4 = 31/4 = 7 3/4

The correct result would be 7 3/4. add me as a friend 
4 0
3 years ago
PLEASE HELP I DONT UNDERSTAND
Annette [7]

Answer:

y = -x + 1

Step-by-step explanation:

eqn of line: y=mx+c

perpendicular, m1 x m2 = -1

m × 1 = -1

m = -1

y=-x+c

sub x=-5, y=6

6 = -(-5) +c

6 = 5 + c

c = 1

y = -x + 1

6 0
3 years ago
Mrs.Isoceles has graded 20% of her 150 students papers how many papers does she still need to grade
Daniel [21]
The answer is 30. you can find the unit rate but the calculator was invented a long time ago so i used that ;)
3 0
3 years ago
Read 2 more answers
5x + y =7<br> 20x + 2 = y
kodGreya [7K]

Answer:

y = 6

x = 0.2

Step-by-step explanation:

5x + y =7

20x + 2 = y

5x(4) + y(4) = 7(4)

20x + 4y = 28

(20x = 28 - 4y) = (20x = y - 2)

28 - 4y = y - 2

30 - 4y = y

30 = 5y

y = 6

5x + y =7

20x + 2 = y

y = 7 - 5x

7 - 5x = 20x + 2

5 - 5x = 20x

5 = 25x

x = 0.2

4 0
3 years ago
Pls help With this question thank you
Lapatulllka [165]

Answer:

CD=4 \text{ cm }

Step-by-step explanation:

We have a similarity of triangles. Once the side BC and ED are parallel,

$\frac{BC}{AC} =\frac{ED}{AD} $

$\frac{10}{AC} =\frac{5}{4} $

Once AC=AD+CD \Rightarrow AC=4+CD

$\frac{10}{4+CD} =\frac{5}{4} $

5CD+20=40

5CD=20

CD=4 \text{ cm }

6 0
4 years ago
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