Where do I get the second number from? I’m confused lol

Answer:

Step-by-step explanation:

I can't believe I'm doing this for 5 points, but ok!

For the first 3, we are going to multiply to find the value of that 3 x 3 matrix by picking up the first 2 columns and plopping them down at the end and then multiplying through using the rules for multiplying matrices:

[tex]\left[\begin{array}{ccccc}7&4&6&7&4\\-4&8&9&-4&8\\1&8&7&1&8\end{array}\right][/tex]  and from there find the sum of the products of the main axes minus the sum of the products of the minor axes, as follows (I'm not going to state the process in the next 2 problems, so make sure you follow it here. This is called the determinate. The determinate is what you get when you evaluate or find the value of a matrix. Just so you know):

[tex](7*8*7)+(4*9*1)+(6*-4*8)-[(1*8*6)+(8*9*7)+(7*-4*4)][/tex] which gives us:

392 + 36 - 192 - [48 + 504 - 112] which simplifies to

236 - 440 which is -204

On to the second one:

[tex]\left[\begin{array}{ccccc}-8&-4&-1&-8&-4\\1&7&-3&1&7\\8&9&9&8&9\end{array}\right][/tex] and multiplying gives us

[tex](-8*7*9)+(-4*-3*8)+(-1*1*9)-[(8*7*-1)+(9*-3*-8)+(9*1*-4)][/tex] which gives us:

-504 + 96 - 9 - [-56 + 216 - 36] which simplifies to

-417 - 124 which is -541, choice c.

Now for the third one:

[tex]\left[\begin{array}{ccccc}-2&-2&-5&-2&-2\\2&7&-3&2&7\\8&9&9&8&9\end{array}\right][/tex] and multiplying gives us

[tex](-2*7*9)+(-2*-3*8)+(-5*2*9)-[(8*7*-5)+(9*-3*-2)+(9*2*-2)][/tex] which gives us:

[tex]-126+48-90-[-280+54-36][/tex] which simplifies to

-168 - (-262) which is 94, choice c again.

Now for the last one. I'll show you the set up for the matrix equation; I solved it using the inverse matrix. So I'll also show you the inverse and how I found it.

[tex]\left[\begin{array}{cc}-4&-5&\\-6&-8\\\end{array}\right][/tex] [tex]\left[\begin{array}{c}x\\y\\\end{array}\right][/tex] = [tex]\left[\begin{array}{c}-5\\-2\\\end{array}\right][/tex] and I found the inverse of the 2 x 2 matrix on the left.

Find the inverse by:

* finding the determinate

* putting the determinate under a 1

* multiply that by the "mixed up matrix (you'll see...)

First things first, the determinate:

|A| = (-4*-8) - (-6*-5) which simplifies to

|A| = 32 - 30 so

|A| = 2; now put that under a 1 and multiply it by the mixed up matrix. The mixed up matrix is shown in the next step:

[tex]\frac{1}{2}\left[\begin{array}{cc}-8&5\\6&-4\end{array}\right][/tex]  (to get the mixed up matrix, swap the positions of the numbers on the main axis and then change the signs of the numbers on the minor axis). Now we multiply in the 1/2 to get the inverse:

[tex]\left[\begin{array}{cc}-4&\frac{5}{2}\\3&-2\\\end{array}\right][/tex] Multiply that inverse by both sides of the equation. This inverse "undoes" the matrix that's already there (like dividing the matrix that's already there by itself) which leaves us with just the matrix of x and y. Multiply the inverse matrix by the solution matrix:

[tex]\left[\begin{array}{c}x&y\end{array}\right] =\left[\begin{array}{cc}-4&\frac{5}{2} \\3&-2\end{array}\right] *\left[\begin{array}{c}-5&-2\\\end{array}\right][/tex] and that right side multiplies out to

x = 20 - 5 which is

x = 15 and

y = -15 + 4 which is

y = -11

(It works, I checked it)

Answer:

Side length ≈ 12.04

Step-by-step explanation:

145 = x²

144 is the closest  square, with the root 12

The square root of 145 is approximately 12.04

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

The approximate side length is 12.0 in

Step-by-step explanation:

The area of a square is given by

A = s^2  where s is the side length

145 = s^2

Taking the square root of each side

sqrt(145) = sqrt(s^2)

12.04159458 = s

The approximate side length is 12.0 in

Answer:

Step-by-step explanation:

Well I can show you by example. Try 28

a = 2

b = 8

2 - 2*8 = 2 - 16 = -14

- 14 is divisible by 7. You get - 2.

That means that 28 is also divisible by 8

We'll try one more. Try 56

a = 5

b = 6

5 - 2*6 = 5 - 12 = - 7

- 7 is divisible by 7 so 56 must be as well. What I'm wondering is if the rule in some form works for 735 and if it does how?

a = 73

b = 5

73 - 10 = 63

63 is divisible by 7 (giving 9)

so 10*73 + b is divisible by 7.

Try something a bit harder.

115444

a = 11544

b = 4

a - 2*4

11544 - 8

11536 / 7

1648 which works perfectly.

115444 is divisible by 28 which is a multiple of 7

Really amazing! Thanks for posting.

Answer:

How can postulates and theorems relating to similar and congruent triangles be used to write a proof? If the three sets of corresponding sides of two triangles are in proportion, the triangles are similar. ... If the three sets of corresponding sides of two triangles are in proportion, the triangles are similar.

Step-by-step explanation:

Hope this helps :D good luck!!

Answer:

B

Step-by-step explanation:

n is the number of litres.

if you substitute 1 for 'n' then you will get :

C = 8 + 1.5(1)

C = $9.5

$9.50 for every litre

Answer:

C is correct

Step-by-step explanation:

The $8 charge is only once regardless of how many liters are ordered, so only answer C works.

Answer:

x^2+3x+3

Step-by-step explanation:

f(x) = 3x - 1

g(x) = x^2 + 4

f(x) + g(x) = 3x-1+ x^2 +4

                 Combine like terms

                   = x^2+3x+3

Answer:

All of them except 12:25 simply to 2:5. So 12:25 is the odd one out.

Answer:

[tex] {(x - y)}^{2} \\ = (x - y)(x - y)[/tex]

open the brackets:

[tex] = ( {x}^{2} - xy - xy + {y}^{2} ) \\ = {x}^{2} - 2xy + {y}^{2} [/tex]

Answer:

Step-by-step explanation:

I am not sure what your first inequality is saying y≤2x +7 or y≥2x+7

-the equation y> -3x-2 , has a negative slope m= -3 (the line is going down from left to right if is a negative slope) and it has to be a dotted line( <, or > is a dotted line, ≤, or ≥ is a solid line) so the answer must be either A or D

-if the second equation is y≤2x +7 then the answer is D because y has to be less than 2x+7 the area under the line will be include in the solution

--if the second equation is y≤2x +7 then the answer is A because y has to be greater than 2x+7 the area above the line will be include in the solution

Answer:

1 4/5

Step-by-step explanation:

2x+7>-3x-2

2x+3x>-2-7

5x/5>-9/5

=1 4/5

Thanks Hope It Help

Answer:

So if PT=TQ and TQ=7x-9

PT=5x+3=TQ=7x-9

5x+3=7x-9

minus 5x both sides

3=2x-9

add 9 both sides

12=2x

divide 2

6=x

PT=5x+3

PT=5(6)+3

PT=30+3

PT=33

PT=QT=33

x=6

Answer:

C.47,5cm²

Step-by-step explanation:

[tex]\\ \sf\longmapsto f(2+h)[/tex]

[tex]\\ \sf\longmapsto 4(2+h)-3[/tex]

[tex]\\ \sf\longmapsto 4h+8-3[/tex]

[tex]\\ \sf\longmapsto 4h+5[/tex]

Answer:

there is a 25% decrease in books being read

Answer:

Step-by-step explanation:

[tex]f(x)=\frac{x+9}{7-4x} \\put ~f(x)=y\\flip~x~and~y\\f(y)=x\\y=f^{-1}(x)\\y=\frac{x+9}{7-4x} \\flip~x~and~y\\x=\frac{y+9}{7-4y} \\x(7-4y)=y+9\\7x-4xy=y+9\\-4xy-y=9-7x\\or\\4xy+y=7x-9\\y(4x+1)=7x-9\\y=\frac{7x-9}{4x+1} \\or~f^{-1}(x)=\frac{7x-9}{4x+1}[/tex]

Answer:

0.7

Step-by-step explanation:

7/11 = 0.63636363

7/9 = 0.777777778

so a decimal between them will be, 7/10 = 0.7

Answer:

[tex]\frac{y}{2}[/tex]

Step-by-step explanation:

n is doubled: 2n

y added: 2n + y

divided by 2: n + [tex]\frac{y}{2}[/tex]

n subtracted -> final resutl: [tex]\frac{y}{2}[/tex]

Answer:

a union b= {1,2,3,4,5}

a intersection b ={2,3}

Step-by-step explanation:

The union of two sets A and B is a set that contains all the elements of A and B and is denoted by A U B

the set composed of all elements that belong to both A and B is A intersection B (A ∩ B)

Answer:

The choose (C)

F(x)=x/ (x+1)(x-2)

Answer:

let,

√x-5=ky

x=30 when y=2

√30-5=2k

or, k=(√30-5)/2

now, when y=8

√x-5=8×(√30-5)/2

or, √x-5=4√30-20

or, √x=4√30-15

or, x=(4√30-15)²

or, x=47.73..

Answer:

DE = 11

Step-by-step explanation:

DF = DF +EF

4x+2 = x+7 + 7

Combine like terms

4x+2 = x+14

Subtract x from each side

4x+2-x = x+14-x

3x+2 = 14

Subtract 2 from each side

3x+2-2 =14-2

3x=12

Divide by 3

3x/3 = 12/3

x = 4

DE = x+7 = 4+7 =11

Answer:

DE is 11

Step-by-step explanation:

[tex]DE = DF - EF \\ DE = (4x + 2) - 7 \\DE = 4x - 5 [/tex]

But for x:

[tex]4x + 2 = (x + 7) + 7 \\ 4x + 2 = x + 14 \\ 3x = 12 \\ x = 4[/tex]

Therefore:

[tex]DE = (4 \times 4) - 5 \\ = 16 - 5 \\ = 11[/tex]

Answer:

Step-by-step explanation:

the answer is b

Answer:

Step-by-step explanation:

B OR TRUE

Answer:

20×2=40bnmcsshjvghjpiutewqadgjlmbcz

Answer: all real numbers

Step-by-step explanation:

Answer:

easy

Step-by-step explanation:

4ab³6a²b

Answer:

[tex] \frac{12 {a}^{2} {b}^{3} 6 {a}^{2}b }{3ab} \\ thank \: you[/tex]

Answer:

the answer will be

1.2x10⁴

hope it helps

Answer:

We have been provided the number, 3430000. Therefore, the standard form is, 3430000=3.43×106, here, we have moved 6 places to the left. Hence, the standard form of 3430000 is 3.43×106. Note: It is important to note that the standard form of representing numbers is also called scientific form or standard index form.

The question is incomplete. The complete question is :

Let [tex]p(t) = -0.0375t^2 + 0.225t[/tex]  be the density function for the shelf life of a brand of banana which lasts up to 4 weeks. Time, t, is measured in weeks and [tex]$0 \leq t \leq 4$[/tex]. Incorrect answer icon Your answer is incorrect. Find the mean shelf life of a banana using . Round your answer to one decimal place.

Answer:

2.4

Step-by-step explanation:

 Given :

[tex]p(t) = -0.0375t^2 + 0.225t[/tex]

Mean :

[tex]$=\int_0^4 tp (t) \ dt$[/tex]

[tex]$=\int_0^4 t (0.0375 t^2 + 0.225t) \ dt$[/tex]

[tex]$=-0.0375 \int_0^4 t^3 \ dt + 0.225 \int_0^4 t^2 \ dt$[/tex]

[tex]$=-0.0375 \left[ \frac{t^4}{4} \right]^4_0 + 0.225 \left[ \frac{t^3}{3} \right]^4_0$[/tex]

[tex]$=-0.0375 (64) + 0.225 \left( \frac{64}{3} \right)$[/tex]

[tex]$=-2.5 + 4.8$[/tex]

= 2.4

Therefore, the mean is 2.4

Answer:

Which one have same variable gather or decrease up

Step-by-step explanation:

2x^2-4.6x^2=1.4x^2

-7x+7x=0

1.4x^2+2<0

x<0

Answer:

Step-by-step explanation:

0.9*2b = 1.8b

0.9*-1 = -0.9

So far we have 1.8b-0.9. It can't be simplified further.

Then, we add the 2nd part, -0.5b+1.

We have:

1.8b-0.9-0.5b+1. Next we combine like terms.

1.8b-0.5b = 1.3b.

-0.9+1 = 0.1

Then we put it together.

1.3b+0.1 is our answer.

Hope this helped! Have a nice day :D

Hi there!  

»»————-　★　————-««

I believe your answer is:

1.3b + 0.1

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{Simplifying...}}\\\\0.9(2b-1)-0.5b+1\\--------------\\\rightarrow 1.8b - 0.9 - 0.5b + 1\\\\\rightarrow 1.8b - 0.5b - 0.9 + 1\\\\\rightarrow \boxed{1.3b +0.1}[/tex]

⸻⸻⸻⸻

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.