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3 years ago

Please don’t skip over me! show all work

Mathematics

1 answer:

aleksklad [387]3 years ago

7 0

Answer:

a,c,d

Step-by-step explanation:

$a. \\4i^9+4i^7\\=4i(i^2)^4+4i(i^2)^3\\=4i(-1)^4+4i(-1)^3\\=4i-4i\\=0\\b.\\2i^{18}-3i^{11}\\=2(i^2)^9-3i(i^2)^5\\=2(-1)^9-3i(-1)^5\\=-2+3i\\c.\\7i^{36}-11i^{11}-11i^9\\=7(i^2)^{18}-11i(i^2)^5-11i(i^2)^4\\=7(-1)^{18}-11i(-1)^5-11i(-1)^4\\=7+11i-11i\\=7\\d.\\8i^{22}-1\\=8(i^2)^{11}-1\\=8(-1)^{11}-1\\=-8-1\\=-9$

$2i^{27}+4\\=2i(i^2)^{13}+4\\=2i(-1)^{13}+4\\=-2i+4$

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A (0, 2) and B (6,6) are points on the straight line ABCD.

elena-14-01-66 [18.8K]

Answer:

(18, 14)

Step-by-step explanation:

We know that C and D lie on the line AB and BC = CD = AB. Then we need to use the distance formula and equation of the line AB to find the other two coordinates.

The distance formula states that the distance between two points $(x_1,y_1)$ and $(x_2,y_2)$ , the distance is denoted by: $\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$ . Let's find the distance between A and B:

d = $\sqrt{(6-0)^2+(6-2)^2}=\sqrt{6^2+4^2} =\sqrt{36+16} =\sqrt{52} =2\sqrt{13}$

Now say the coordinates of D are (a, b). Then the distance between D and B will be twice of 2√13, which is 4√13:

4√13 = $\sqrt{(6-a)^2+(6-b)^2}$

Square both sides:

208 = (6 - a)² + (6 - b)²

Let's also find the equation of the line AB. The y-intercept we know is 2, so in y = mx + b, b = 2. The slope is (6 - 2) / (6 - 0) = 4/6 = 2/3. So the equation of the line is: y = (2/3)x + 2. Since (a, b) lines on this line, we can put in a for x and b for y: b = (2/3)a + 2. Substitute this expression in for b in the previous equation:

208 = (6 - a)² + (6 - b)²

208 = (6 - a)² + (6 - (2/3a + 2))² = (6 - a)² + (-2/3a + 4)²

208 = a² - 12a + 36 + 4/9a² - 16/3a + 16 = 13/9a² - 52/3a + 52

0 = 13/9a² - 52/3a - 156

13a² - 156a - 1404 = 0

a² - 12a - 108 = 0

(a + 6)(a - 18) = 0

a = -6 or a = 18

We know a can't be negative so a = 18. Plug this back in to find b:

b = 2/3a + 2 = (2/3) * 18 + 2 = 12 + 2 = 14

So point D has coordinates (18, 14).

8 0

3 years ago

Read 2 more answers

Deluxe River Cruises operates a fleet of river vessels. The fleet has two types of vessels: A type-A vessel has 60 deluxe cabins

bixtya [17]

Answer: It should be used 2 for type-A and 3 for type-B to minimize the cost.

Step-by-step explanation: As it is stipulated, <u>x</u> relates to type-A and y to type-B.

Type-A has 60 deluxe cabins and B has 80. It is needed a minimum of 360 deluxe cabins, so:

60x + 80y ≤ 360

For the standard cabin, there are in A 160 and in B 120. The need is for 680, so:

160x + 120y ≤ 680

To calculate how many of each type you need:

60x + 80y ≤ 360

160x + 120y ≤ 680

Isolating x from the first equation:

x = $\frac{360 - 80y}{60}$

Substituing x into the second equation:

160( $\frac{360 - 80y}{60}$ ) + 120y = 680

-3200y+1800y = 10200 - 14400

1400y = 4200

y = 3

With y, find x:

x = $\frac{360 - 80y}{60}$

x = $\frac{360 - 80.3}{60}$

x = 2

To determine the cost:

cost = 42,000x + 51,000y

cost = 42000.2 + 51000.3

cost = 161400

To keep it in a minimun cost, it is needed 2 vessels of Type-A and 3 vessels of Type-B, to a cost of $161400

8 0

3 years ago

Work out the size of angle x forty two degrees and one hundred and one hundred and twenty three degrees

Snezhnost [94]

Answer:

x = 28

Step-by-step explanation:

With 3 angles I'm guessing its a triangle so all triangles equal 180 degrees

42 + 110 = 152

180 - 152 = 28

3 0

3 years ago

The length of one edge of a cube is 7 units. What is the volume of this cube in cubic units?HELP ME PLEASE JUSTIFY THE ANSWER th

IRISSAK [1]

Answer:

343 cubic units^3

Step-by-step explanation:

its a cube which means all the sides are the same length, multiply lwh (length x width x height), which would be 7x7x7 or 7^3.

5 0

3 years ago

Alex went to the grocery store and bought 5 avocados. He paid $10 and received $4.50 in change. How much did each avocado cost i

Delvig [45]

Answer:

$1.10

Step-by-step explanation:

We have been that Alex went to the grocery store and bought 5 avocados. He paid $10 and received $4.50 in change.

First of all, we will find amount paid for 5 avocados by subtracting $4.50 from $10.

$\text{Amount paid for 5 avocados}=\$10-\$4.50$

$\text{Amount paid for 5 avocados}=\$5.50$

Now, we will divide $5.50 by 5 to find cost of each avocado.

$\text{Cost of each avocado}=\frac{\$5.50}{5}$

$\text{Cost of each avocado}=\$1.10$

Therefore, the cost of each avocado is $1.10.

3 0

3 years ago