nico wanted to determine the number of students in his school who buy school lunch. he walked around the cafeteria one lunch period looking to see whether every fifth person in the cafeteria purchased lunch or brought their own. which method did he use to collect his data? survey simulation experiment observational study

The answer for the first question is A

The answer the second question is D

Step-by-step explanation:

so, let's look at the options.

A. (x+3)/x = 3

that hurts already by just looking at it.

but let's check anyway :

x + 3 = 3x

3 = 2x

and that is only true for one value of x (3/2), but not in general.

so, this is wrong.

B. (x²+5)/5 = x² + 1

x² + 5 = 5x² + 5

x² = 5x²

that is only true for one value of x (0), but not in general.

so, this is wrong.

C. (2x+7)/(2x+9) = 7/9

9(2x+7) = 7(2x+9)

18x + 63 = 14x + 63

4x = 0

that is only true for one value of x (0), but not in general.

so, this is wrong.

D. (-5x - 10)/(x+2) = -5

-5x - 10 = -5(x + 2) = -5x - 10

now this is true in all cases, so this is correct.

make simple :

(a² - 4a + 4) / (a² - 4)

with a little bit of experience you see right away that

a² - 4a + 4 = (a - 2)²

as we know from the generic squaring

(a - b)² = a² - 2ab + b² : a perfect fit.

and

(a² - 4) = (a + 2)(a - 2)

as we know from the generic factor multiplying

(a+b)(a-b) = a² + ab - ab - b² = a² - b² : a perfect fit.

so, the given expression is actually

(a - 2)² / ((a - 2)(a + 2)) = ((a-2)(a-2)) / ((a-2)(a+2))

and so, after eliminating one (a-2) term in the numerator and in the denominator the following remains :

(a - 2) / (a + 2)

and that is answer A

Answer:

6 x (3j + 5+ 4j)

6 x(8j+4j)

6 x 12

72

Step-by-step explanation:

hope this helps

Answer:

Number of comic books is 75.

Original price of each comic book is 4$.

Step-by-step explanation:

There were 75 comics in the box originally.

An equation is the statement of equality between two expressions consisting of variables and/or numbers.

Given that, Tayla purchased a large box of comic books for $300. She gave 15 of the comic books to her brother and then sold the rest on an internet website for $330, making a profit of $1.50 on each one.

Let x be the number of comics originally

(x - 15) is the number of comics sold.

Original price of each comic = 300/x

Price of comics which she gave to brother = 15*300/x

Original price of all the books that has been sold  = 300 - 15*300/x

Tayla's profit = 330 - (300 - 15*300/x) = 30 + 15*300/x

Number of comics sold = (30 + 15*300/x)/1.5

Equation will be,

(30 + 15*300/x)/1.5 = x - 15

20 + 3000/x = x - 15

(x² - 15x - 3000)/x = 20

x² - 35x - 3000 = 0

On factorizing the quadratic equation, we get,

x = 75 or -40 (Neglecting -40, because number of books can't be negative)

Hence, there were 75 comic books in the box originally.

For more references on Equations, click;

https://brainly.com/question/10413253

#SPJ5

Answer:

Why don't know wt is equal to..

Step-by-step explanation:

3(x + 4) - (2x + 7)

3x + 12 - 2x - 7

1x + 5

x + 5

Answer:

3 years.

Step-by-step explanation:

Answer

3 years

Step by step explanation

Interest = 1740 - 1200

= 540

SI = prt/100

540 = 1200*15*t/100

540 = 12*15*t

540 = 180*t

t = 540/180

t = 3 yrs

Answer:

-7/4 is between -2 and -1 1/2

11/4 is in between 2 1/2 and 3

Step-by-step explanation:

-7/4 is -1.75 which means its right before -2

11/4 is 2.75 which means it's right before 3

Answer:

Its a triangle to be specific its a scalene triangle

Step-by-step explanation:

Answer:

Week 1 and Week 2.

Step-by-step explanation:

Answer:

the LCM is :

1. 144

2.40

3.870

4. 63

5.216

6.150

7. 112

8.162

9. 96

10. 40

9514 1404 393

Answer:

  27/8 = 3 3/8 miles

Step-by-step explanation:

To find the rate in miles per hour, divide miles by hours.

  (3/8 mi)/(1/9 h) = (3/8)·(9/1) mi/h = 27/8 mi/h = 3 3/8 mi/h

You can walk 3 3/8 miles in 1 hour at that rate.

Answer:

5^(3) is the exponent form which equals 125desks

Step-by-step explanation:

A row has 5 desks

A classroom has 5 rows of desks= 5*5 desks

The school has 5 classrooms

=5*5+5*5+5*5+5*5+5*5 desks

=5^(2)+5^(2)+5^(2)+5^(2)+5^(2)

=5[5^(2)]

=5^(3) = 125 desks

Answer:

y = 8

Step-by-step explanation:

As MTW and BGK are congruent

angle T = angle G

4x - 3 = 45

in triangle MTW

angle M = 180 - (T + W)

= 180  - (45 + 41)

= 180 - 86

= 94

and angle M = B

11y + 6 = 94

11y = 94 - 6

11y = 88

y = 8

Answer:

3  ( x  +  29 )

Step-by-step explanation:

The best I can do is factor them, hope it helps!

Answer:

[tex]\frac{400}{(10\sqrt{2} + 14\sqrt{3}) }= h[/tex]   or  10.42 = h

Step-by-step explanation:

The area of a trapezoid is [tex]A = \frac{1}{2}h(b_{1} + b_{2} )[/tex].

[tex]200 = \frac{1}{2}h(10\sqrt{2} + 14\sqrt{3})[/tex]

[tex]400 = { h(10\sqrt{2} + 14\sqrt{3} )[/tex]             Multiply both sides by 2

[tex]\frac{400}{(10\sqrt{2} + 14\sqrt{3}) }= h[/tex]

 [tex]\frac{400}{38.39} = h[/tex]

10.42 = h  

Answer:

Step-by-step explanation:

Even though this seems like a crazy trick question it isn’t. An empty pool with a closed drain takes 3 hours to fill. A full pool with and open drain takes 4 hours to empty. So to fill and empty pool with an open drain, i’d say in my opinion it’d either take 7 hours or you wouldnt be able to fill it at all. I mean it’s an open drain

hope this helped :3

:3 byeeeeeeeeeeeeeeeee

Answer:

The sales tax percentage is 7%

Step-by-step explanation:

$27 x 7% = $1.89

add the sales tax to the cost of the product and it will be

$28.89 , hope that helped , have a good day :D !!

Answer:

Can anyone agree this image is blurry? Can you send it again but not blurry this time? Sorry!

Step-by-step explanation:

Answer:

f(66) = -3

Step-by-step explanation:

f(x) = 8 - x/6                     Substitute 66 for the vale of x and solve

f(66) = 8 - 66/6

f(66) = 8 - 11

f(66) = -3

Answer:

To complete the square, you always want to add [tex](\frac{a}{2} )^{2}[/tex], where a is the coefficient of x.

In this case, the coefficient of x is -1.

Thus,

[tex]y=x^2-x+1[/tex]

[tex]y=x^2-x+(\frac{-1}{2})^2 +1-(\frac{-1}{2})^2[/tex]

[tex]y=(x-\frac{1}{2})^2+1-\frac{1}{4}[/tex]

[tex]y=(x-\frac{1}{2})^2+\frac{3}{4}[/tex]

Answer:

AAS Congruence Theorem

Step-by-step explanation:

the lines in the angle show similarity. so angle FGJ= angle HJG, similarly, angle F= angle H.GJ is the same as JG so this side of both triangles is congruent. since the order of congruency is the same (triangle GHJ: angle H, angle HJG, then JG; triangle JFG: angle F, angle FGJ, then GJ) and the congruent side length isn't between the congruent angles, it's AAS

Answer:

a

Step-by-step explanation:

r and t are same- side exterior angles and sum to 180 , so

t + r = 180 , that is

t + 91 = 180 ( subtract 91 from both sides )

t = 89

t and u are vertically opposite angles and are congruent , so

u = t = 91

Then

t + u = 89 + 89 = 178 → a

Answer:

Step-by-step explanation:

Elimination sounds the easiest for y:

[tex]I - 2II: 2x+3y -2x -2y = 15-12 \rightarrow y= 3[/tex]

Now we got one value, let's replace in one of the two and find the second

[tex]II: x+(3)=6 \rightarrow x=3[/tex]

Answer:

[tex]2x + 3y = 15...(1) \\ x + y = 6...(2) \\ 2 \times (2) \\ 2x + 2y = 12...(3) \\ (1) - (3) \\ 0 + 3y - 2y = 15 - 12 \\ \color{red} \boxed{ y = 3 }\\ sub \: in \: (2) \\ x + 3 = 6 \rightarrow \: x = 6 - 3 \\ \color{green} \boxed{ x = 3 }[/tex]

Step-by-step explanation:

just like an equation.

5x - 7 > 4x + 8 | -4x + 7

x > 15

and that is your result.

in contrast to an equation, an inequality delivers a range as result and not a single point.

Answer:

[tex]\huge\boxed{\sf x > 15}[/tex]

Step-by-step explanation:

5x - 7 > 4x + 8

Subtract 4x to both sides, and Add 7 to both sides

5x - 4x > 8 + 7

x > 15

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

3 loops

Step-by-step explanation:

1.2x = 3.6 [Setting up an equation]

x = 3 [dividing both sides by 1.2]

Have a nice day!

     I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)

- Heather

Answer: 4k^2 - 9k - 9 = 0

Step-by-step explanation:

lmk if i was right please and ty

Answer:

Step-by-step explanation:

Answer:

Step-by-step explanation:

Answer:

  m∠X = 70°

Step-by-step explanation:

In congruent triangles, corresponding parts have the same measures. In ΔABC and ΔXYZ, the corresponding parts are ...

  ∠A = ∠X = 70° . . . . . . . . . . . matches choice A

  ∠B = ∠Y = (90° -70°) = 20°

  ∠C = ∠Z = 90°

  AB = XY = √(3.5² +9.6²) ≈ 10.22 cm

  BC = YZ = 9.6 cm

  AC = XZ = 3.5 cm

Answer:

 m∠X = 70°

Step-by-step explanation:

In congruent triangles, corresponding parts have the same measures. In ΔABC and ΔXYZ, the corresponding parts are ...

 ∠A = ∠X = 70° . . . . . . . . . . . matches choice A

 ∠B = ∠Y = (90° -70°) = 20°

 ∠C = ∠Z = 90°

 AB = XY = √(3.5² +9.6²) ≈ 10.22 cm

 BC = YZ = 9.6 cm

 AC = XZ = 3.5 cm

Answer:

3/4 ÷ 1/8 = 6

Step-by-step explanation:

first you would have to figure out how to make them even factors.

6/8 ÷ 1/8

Then you would divide, and get 6.