help me pls with math

86%

30 students in the class with a mean average of 70% can be expressed as:

total class percent / 30 = 70%

Rearranged, this gives that the class achieved a total of 30x70 or 2100%.

20 boys in the class with a mean average of 62% can be expressed as:

total boys percent / 20 = 62%

Rearranged, this gives that the boys achieved a total of 20x62 or 1240%.

This means that the girls achieved 2100 - 1240 so 860%.

Because there are 30 students and 20 boys, there are 10 girls.

Then work out the mean with a total of 860% and 10 girls.

860/10 = 86%.

Answer:

the slope=-1 the slope perp=1

Step-by-step explanation:

to find slope perpendicular you just have to multiply your slope by something and have it equal -1

for example

1/2x=-1

the slope perpendicular to a line with the slope of 1/2 would be -2 beacause 1/2x-2=-1

so the slope x perpendicular slope = -1

Answer:

Step-by-step explanation:

around 19 minutes ^^

(18.85 minutes)

Mary can allocate to each chore around 18.85 minutes.

The unitary method is a method for solving a problem by the first value of a single unit and then finding the value by multiplying the single value.

It is given that Mary has 2 1/5 hours before she needs to meet her friend. She needs to take care of 7 chores before then.

Hence, we get

2 and 1/5 hours = 132 minutes (120 + 12)

thus, Mary will have 132/7 = 18.85714285714286 minutes for each chore.

Or around 18.85 minutes for each chore

Therefore, she can allocate to each chore around 18.85 minutes.

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Answer:

344444444433333338694

Step-by-step explanation:

Answer: y = -3x+5

Step-by-step explanation:

Answer:

6.6/100 or 3.3/5

Step-by-step explanation:

6.6% or 6 3/5% now since those are all out of 100 (since percentages) you just put #/100 and get your fraction

Answer:

X=(-1.5, 7.5)

Step-by-step explanation:

Simplifying

4x2 + -24x + -45 = 0

Reorder the terms:

-45 + -24x + 4x2 = 0

Solving

-45 + -24x + 4x2 = 0

Solving for variable 'x'.

Factor a trinomial.

(-3 + -2x)(15 + -2x) = 0

Set the factor '(-3 + -2x)' equal to zero and attempt to solve:

Simplifying

-3 + -2x = 0

Solving

-3 + -2x = 0

Move all terms containing x to the left, all other terms to the right.

Add '3' to each side of the equation.

-3 + 3 + -2x = 0 + 3

Combine like terms: -3 + 3 = 0

0 + -2x = 0 + 3

-2x = 0 + 3

Combine like terms: 0 + 3 = 3

-2x = 3

Divide each side by '-2'.

x = -1.5

Simplifying

x = -1.5  

Set the factor '(15 + -2x)' equal to zero and attempt to solve:

Simplifying

15 + -2x = 0

Solving

15 + -2x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-15' to each side of the equation.

15 + -15 + -2x = 0 + -15

Combine like terms: 15 + -15 = 0

0 + -2x = 0 + -15

-2x = 0 + -15

Combine like terms: 0 + -15 = -15

-2x = -15

Divide each side by '-2'.

x = 7.5

Simplifying

x = 7.5

Solution

x = {-1.5, 7.5}

Answer:

3 – x

Step-by-step explanation:

A number in this case we will as x. And 3 less than x is -

3 – x

x - 3

Hope i helped ya!

Answer:

1024

Step-by-step explanation:

The expression can be written as [tex]8 * 2^7[/tex]

An algebraic expression known as a polynomial requires that all of its exponents be whole numbers. Any polynomial must have variable exponents that are non-negative integers. Although a polynomial contains variables and constants, we are unable to divide a polynomial by a variable.

Example: The standard form of the polynomial 5 + 2x + x² is expressed.

We shall first determine the polynomial's degree before expressing it in standard form.

The degree of the provided polynomial is two. Write the phrase containing the polynomial's degree.

Given:

8*2^7

The above expression can be written as

[tex]=8 * 2^7[/tex]

= 8 x 128

= 1024.

Hence, the expression can be written as [tex]8 * 2^7[/tex]

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Answer:

y = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex]

Step-by-step explanation:

y = 2x² - 2x - 5 ← factor out 2 from the first 2 terms

 = 2(x² - x) - 5

Using the method of completing the square

add/subtract (half the coefficient of the x- term)² to x² - x

y = 2(x² + 2(- [tex]\frac{1}{2}[/tex] ) x + [tex]\frac{1}{4}[/tex] - [tex]\frac{1}{4}[/tex] ) - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² + 2(- [tex]\frac{1}{4}[/tex] ) - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{1}{2}[/tex] - 5

  = 2(x - [tex]\frac{1}{2}[/tex] )² - [tex]\frac{11}{2}[/tex] ← in vertex form

Answer:

5 Motorcycles are used

30÷6= 5

5×5= 25

30-24=5

so the answer is 5

Answer:

5 out of the 30 motorcycles are used

Step-by-step explanation:

First, we should look at what we know. We know that there are 30 motorcycles in total. As a fraction, that'd be 30/30. We also know that of that 30, the equivalent of 5/6 are brand new.

Our next step is to figure out how much 5/6 is out of 30. Since we know that in total there 30/30 motorcycles, we need to convert 5/6 to have a denominator of 30. So what times 6 equals 30.

30 ÷ 6 = ?    opposite of 6 x ? = 30

5                   divide

So now we now that 6 times 5 equals 30. What we do to the denominator we must do to the numerator.

[tex]\frac{5}{6}[/tex] × [tex]\frac{5}{5}[/tex]    

[tex]\frac{25}{30}[/tex]

Now we know that 25 of the 30 motorcycles are new and all we need to do is subtract that 25 from the total 30 to get 5. This tells us that 5 of the total motorcycles are used.

I hope this helped :)

Answer:

the atoms can have different numbers of valence electrons

Answer:

72m

Step-by-step explanation:

since 5cm is 6m, just take 5 and make it 6, so 10cm is 12m and 5cm is 6m

multiply, and you get the answer

Answer:

yes

Step-by-step explanation:

Answer:

Yes

Step-by-step explanation:

Your answer is 5,7... Oh that's wrong you forgot to link a file bud

Answer:

B STEP 2

Step-by-step explanation:

5/8 is not more than 1

If you meant 2x, x is 15; if you meant x^2, the answer is the square root of 30

Answer:

Step-by-step explanation:

Denominators of the fractions are 7 and 3, which are mutually prime numbers.

The LCD is the product of 7 and 3:

Simplify into mixed fraction

[tex]\\ \sf\longmapsto 6\dfrac{5}{7}=\dfrac{47}{7}[/tex]

[tex]\\ \sf\longmapsto 6\dfrac{1}{3}=\dfrac{19}{3}[/tex]

Find LCD

[tex]\\ \sf\longmapsto 7(3)[/tex]

[tex]\\ \sf\longmapsto 21[/tex]

Answer:

"O c. 17.156"

Step-by-step explanation:

    A is not a rational number because it cannot be written as a fraction [with two integers] or an integer (the square root of 15 is equal too 3.87298334...)

   B is not a rational number because it also goes on forever, just like A.

    C is a rational number because it does not go on forever.

    D is like A and B, it goes on forever.

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:

C = 4s + 6a

C = 4(3) + 6(2)

C = 12 + 12

C = 24

Answer:

7+5=12

Step-by-step explanation:

To calculate the mass number of an atom, you have to add the protons and the neutrons. We have 7 neutrons and 5 protons, so your mass number would be 12. Let me know if you have any further questions. :)

Answer:

12x + 3 - 4x - 6 = 5

x=1

5x - 4 + 7 + 6x - 4x = 24

x=3

Answer: ? What are you talking about?

Step-by-step explanation:

Answer:if one part is bigger than the other then its bigger

this should help

Answer:

(8 × 3) + (8×2)

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

-5g -6

Let g= -2

-5 (-2) -6

Multiply

10 -6

4

Answer:

A. 4

Step-by-step explanation:

So, we have an equation with a variable (g), and they've given us the value of g to be -2. All we have to do at this stage is plug in the value of g into the equation.

-5g-6 (g=-2)

-5(-2)-6

10-6=4

Doing the math by plugging in -2, you would get your answer to be 4. Let me know if you see any errors, and if you have any further questions at all.

Please check the attached image for the steps.

Answer = 11/42 = 0.261

____

RainbowSalt2222 ☔

Answer:

$0.52

Step-by-step explanation:

3.19 (headband) - 2.67 (bracelet) = 0.52

Answer:

Step-by-step explanation:

Answer:

96 cm or B

Step-by-step explanation:

Base-l*w, 6*6, 36

Side 1-(h*w)1/2, (30)1/2, 15

Side 2-Same as 1

Side 3-Same as 1

Side 4-Same as 1

15+15=30, 15+15=30, 30+30=60, 60+36=96

96 cm