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2 years ago

Use the formula to evaluate the series 3-9+27-81+...-a8

1 answer:

6 0

In the given series, we see that the first term is 3 and the common ratio between the succeeding terms is -3. To solve for the sum of the first 8 terms, we use the equation,

Sum = (a1)(1 – r^n) / (1 – r)

Substituting the known terms,

Sum = (3)(1 – (-3)^8)/(1 - -3) = -4920

<span>Thus, the answer is -4920.</span>

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The line AB had midpoint (2, 5).<br><br>A has coordinates (1, 2).<br><br>Find the coordinates of B.

sveta [45]

Answer:

The line AB, with A(Ax, Ay), B(Bx, By) and midpoint M(Mx, My) satisfying:

Ax + Bx = 2Mx

Ay + By = 2My

2 + Bx = 2*1

5 + By = 2*2

=> Bx = 0

=> By = -1

=> B(0, -1)

Hope this helps!

5 0

3 years ago

Read 2 more answers

Janet sees a 35% off tag on a $70 hand bag. Janet has $60. If tax is 5%, will she

Natasha_Volkova [10]

______________________________

<h3>= 35% × $70 ÷ 100</h3><h3>= 24.5</h3><h3>= $70 - 24.5</h3><h3>= 45.5</h3><h3>= 5% × 45.5 ÷ 100</h3><h3>= 2.275</h3><h3>= 2.275 + 45.5</h3><h3>= ~$47.775</h3><h3>= <u>$</u><u>48</u></h3><h3>Janet Will Have Enough Money Left Over For A Movie Ticket.</h3>

______________________________

4 0

2 years ago

Line WX and line YZ intersect at point V. If angle WVY = 4a + 58 and angle XVY = 2b - 18, find the values of a and b so that lin

amid [387]

we know that

If line WX is perpendicular to line YZ

then

see the attached figure to better understand the problem

m∠WVY=90°--------> 4a+58=90-----> 4a=90-58-----> a=32/4------> a=8°

m∠XVY=90°--------> 2b-18=90----> 2b=90+18------> b=118/2-------> b=59°

therefore

<u>the answer is</u>

a) The value of a is 8 degrees

b) The value of b is 59 degrees

5 0

2 years ago

A radio tower is located 300 feet from a building. From a window in the building, a person determines that the angle of elevatio

DerKrebs [107]

Answer:

The tower is approximately 381 feet high.

Step-by-step explanation:

Refer to the sketch attached. The height of the tower can be found in two parts:

The part above the window, and
The part under the window.

Each part can be seen as a leg of a right triangle. The other leg is the distance between the building and the tower and is 300-feet long. The angle opposite to the leg is given.

The length of the upper part is $300\cdot \sin{42^{\circ}}$ feet.
The length of the lower part is $300\cdot \sin{37^{\circ}}$ .

The height of the tower is the sum of the two parts:

$300\cdot \sin{42^{\circ}} + 300\cdot \sin{37^{\circ}} = 300(\sin{42^{\circ}}+\sin{37^{\circ}}) = 381$ feet.

4 0

3 years ago

I need helpplz anyone?

Yuri [45]

I can't see the picture that well. maybe you can put a better picture plz

3 0

2 years ago