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3 years ago

If the nth term of a sequence is 28-3n what is the 7th term?

2 answers:

5 0

Erms.
For 3, 9, 27, ... the common ratio is 3 because:
3 X 3 = 9
9 X 3 = 27
So to find the 7th term you can do it two ways:
One way:
3 is the 1st term, 9 is the 2nd term, 27 is the 3rd term so then
4th term: 27 X 3 = 81
5th term: 81 X 3 = 243
6th term: 243 X 3 = 729
7th term: 729 X 3 = 2,187
Another way:
You can use the explicit formula
a
n
=
a
1
⋅
r
n
−
1
, where
a
n
is the nth term,
a
1
is the first term, n is the number of the term, and r is the common ratio
so
a
7
=
3
⋅
3
7
−
1

a
7
=
3
⋅
3
6

a
7
=
3
⋅
729

a
7
=
2
,
187

Both ways get you to the same answer that the 7th term in that geometric sequence is 2, 187 .

expeople1 [14]3 years ago

3 0

Answer:

Step-by-step explanation:

28-3(7)

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In parallelogram ABCD, AB = 16 cm, DA = 3<img src="https://tex.z-dn.net/?f=%5Csqrt%7B2%7D" id="TexFormula1" title="\sqrt{2}" alt

Murljashka [212]

Answer:

length of segment YZ is 8 cm

Step-by-step explanation:

given data

AB = 16 cm

DA = 3 $\sqrt{2}$ cm

AB and DA form interior angle = 45-degre

WX ≠ YZ

WX = 16 cm

to find out

length of segment YZ

solution

area of △ABD is the same as the area of △BCD

and

area of △ABD is express as

area of △ABD = AB × AD × sin(45) ÷ 2 ............1

put here value

area of △ABD = 16 × 3√2 × sin(45) ÷ 2

area of △ABD = 24

and

area of the parallelogram is

area of the parallelogram = 24 × 2

area of the parallelogram = 48

now we will consider here YZ = x

and Since ZY XW is isosceles trapezoid

so here we can say that

WM = ZM = (16 - x) ÷ 2 .......................2

so area of trapezoid will be

area of trapezoid = $\frac{ZY + WX }{2} \times ZM$ .......................3

area of trapezoid = $\frac{x+16}{2} \times \frac{16 - x}{2}$

48 = $\frac{x+16}{2} \times \frac{16 - x}{2}$

solve it we get

x = 8

so length of segment YZ is 8 cm

7 0

2 years ago

Gabrielle is 7 years younger than Mikhail. The sum of their ages is 67. What is Mikhail‘a age

weqwewe [10]

Answer:

Step-by-step explanation

Mikhail is 37

Gabrielle is 30

37+30= 67

6 0

1 year ago

Identify a possible first step using the elimination method to solve the system and then find the solution to the system. 3x - 5

Nastasia [14]

Answer:

see explanation

Step-by-step explanation:

Given the 2 equations

3x - 5y = - 2 → (1)

2x + y = 3 → (2)

Multiply (2) by 5 will eliminate y when added to (1), that is

10x + 5y = 15 → (3)

Add (1) and (3) term by term

(3x + 10x) + (- 5y + 5y) = (- 2 + 15)

13x = 13 ( divide both sides by 13 )

x = 1

Substitute x = 1 into (2) for corresponding value of y

2 + y = 3 ⇒ y = 3 - 2 = 1

Solution is (1, 1)

7 0

3 years ago

Read 2 more answers

Find the exact value of sin (x-y) if sinx=4/9 and siny=1/4

Svetach [21]

Answer:

sin(x - y) = 0.21

Step-by-step explanation:

we have the sin values which we need to get cos values

sin (A-B) = sin A cos B - sin B cos A

sin² A + cos² A = 1

sin x = 4/9

cos² x = 1 - sin² x = 1 - 16/81 = 65/81

cos² x = 65/81

cos x = √65/9

sin y = 1/4

cos² y = 1 - sin² y = 1 - 1/16 = 15/16

cos² y = 15/16

cos y = √15/4

sin(x − y) = sin x cos y - sin y cos x

sin(x - y) = 4/9 √15/4 - 1/4 √65/9

sin(x - y) = (4√15-√65)/36

sin(x - y) = 0.21

socratic Narad T

8 0

2 years ago

Find the radius of the sphere with the given volume<br><br>volume= 9/16 (pie symbol)ft cubed

xz_007 [3.2K]

Remember, the volume formula of a sphere is $\frac{4}{3} \pi r^{3}$ .

Set that equation equal to whatever volume they give you and solve for r.

$\frac{4}{3} \pi r^{3}$ = $\frac{9}{16} \pi$

Now solve for r! I know you can do this. If you need help, just comment.

5 0

3 years ago