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3 years ago

Given a = 2i+j – 2k b= -1 – 7j+k Find a x b

Mathematics

1 answer:

castortr0y [4]3 years ago

7 0

Step-by-step explanation:

a = 2i + j - k

b = -1 -7j + k

a × b = (2i + j - k) (-1 + 7j + k)

-2i + 14ij + 2ik - j + 7j^2 + jk + k -7jk - k^2

-2i + 14ij + 2ik -j +7j^2 +jk - 7jk + k - k^2

-2i + 14ij + 2ik - j +7j^2 - 6jk + k - k^2

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anygoal [31]

The answer is 35 degrees.

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3 years ago

What quadratic equation could be solved to find any solutions to the system of equations?

Kipish [7]

Answer:

Step-by-step explanation:

x²+7x-11=-5x+6

x²+7x+5x-11-6=0

x²+12x-17=0

$x=\frac{-12\pm \sqrt{12^2-4*1*(-17)} }{2*1} \\=\frac{-12 \pm \sqrt{144+68} }{2} \\=\frac{-12 \pm \sqrt{212}}{2} \\=\frac{-12+2\sqrt{53}}{2}\\=-6 \pm \sqrt{53}$

7 0

3 years ago

A gardener wants to try different combinations of fertilizer (none, 1 cup, 2 cups) and mulch (none, wood chips, pine needles, pl

sattari [20]

Answer:

Step-by-step explanation:

First lets identify the number of treatments possible.

1st possibility: no fertilizer, no mulch

2nd possibility: no fertilizer, wood chips

3rd possibility: no fertilizer, pine needles

4th possibility: no fertilizer, plastic

5th possibility: 1 cup fertilizer, no mulch

6th possibility: 1 cup fertilizer, wood chips

7th possibility: 1 cup fertilizer, pine chips

8th possibility: 1 cup fertilizer, plastic

9th possibility: 2 cup fertilizer, no mulch

10th possibility: 2 cup fertilizer, wood chips

11th possibility: 2 cup fertilizer, pine chips

12th possibility: 2 cup fertilizer, plastic

Or we can simply calculate no. of possibilities by elements in set a x elements in set b

Total no. of possibilities = 3 x 4 = 12

To find no. of plants for each treatment divide total number of plants by the total treatments possible.

No. of plants for each treatment = total number of plants/ total number of treatments possible

No. Of plants for each treatment = 60/12

No. of plants for each treatment = 5

8 0

3 years ago

consider the equation is Y equals 1/square root of x and y=x-2. approximate solution of the system equations

emmasim [6.3K]

Answer:

$x=1$ and $x=4$

Step-by-step explanation:

We have the following system of equations:

$y=\sqrt{x}$ and $y=x-2$

To solve the problem, we need to equal the two equations:

$x-2=\sqrt{x}$ ⇒ $(x-2)^{2} =x$ ⇒ $x^{2} -4x + 4 = x$

⇒ $x^{2} -5x + 4 = 0$

So you need to find two numbers that added equal to 5 and multiplied equal to 4. These two numbers are $x=-1$ and $x=-4$ .

Then, the factorized form of the polynomial is: $(x-1)(x-4)$ .

The, the solution to the system of equations is: $x=1$ and $x=4$ .

5 0

3 years ago

Help asap plzz<br> -3x + 7 = -8

viva [34]

Answer:

x=5

Step-by-step explanation:

-3x+7=-8

Bring 7 to the other side, it becomes negative

-3x=-8-7

Signs are same on rhs so u add

-3x = -8+-7= -15

Bring -3 to the other side n divide

therefore,

x=-15/-3

= +5 (two negatives become positive)

Hope it helps!

8 0

3 years ago

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