40. Which families of plane figures given below are NOT always similar?
A. Squares
C. Equilateral triangles
B. Circles
D. rectangle​

Answer:

Triangle

Step-by-step explanation:

Has 120° degrees of rotation and measure of the central angle and has 3-fold rotational symmetry

Answer:

Yes

Step-by-step explanation:

Because 12/18 = 2/3..(cancel 12 and 18 by 6)

Answer:

yes

Step-by-step explanation:

2x6=12

3x6=18

6 is the multiplying number

( the 2 equations are the same amount )

Answer:

x = -67/15 = -4-46667

Step-by-step explanation:

4(-3x+1) - 3x = 71

4*-3x + 4*1 - 3x = 71

-12x + 4 - 3x = 71

-15x = 71-4

-15x = 67

x = 67/-15

x = -4.46667

check:

4(-3*-4.46667 + 1) - 3*-4.4666= 71

4(13.4+1) + 13.4 = 71

4*14.4 + 13.4 = 71

57.6 + 13.4 = 71

Answer:

The answer is B)

[tex]y = - \frac{1}{2}x + 8[/tex]

Answer:

B.  y = -[tex]\frac{1}{2}[/tex]x + 8

Step-by-step explanation:

The line is perpendicular to line whose equation is:

y = 2x + 4 and;

passes through point (4,6) .

The product slopes of two perpendicular lines is -1.

The slope of the line whose equation is y = 2x + 4 is; 2

Let the slope of the perpendicular line (l2) be [tex]m_{l2}[/tex]

[tex]m_{l2} * 2 = -1[/tex]

[tex]m_{l2}[/tex] = [tex]-\frac{1}{2}[/tex]

Taking another point xy on line l2;

[tex]\frac{y - 6}{x - 4} = -\frac{1}{2}[/tex]

Cross multiplying this gives;

y = -[tex]\frac{1}{2}[/tex]x + 8 which is the equation of the perpendicular line!

Answer:

z=-3

Step-by-step explanation:

z=(-3)^2 - 3(4)

z=9 - 12

z=-3

Answer:

The correct answer is 8 servings of pancakes.

Step-by-step explanation:

If each serving of pancakes calls for 1/4 cup of flour, to find how many servings can be made with 2 cups of flour, we should divide 2 cups by 1/4 cup.

To do this, we can first convert 1/4 to a decimal by dividing the numerator by the denominator.  

1/4 = 0.25

Next, we can go ahead with the division.

2 / 0.25 = 8

Therefore, 8 servings of pancakes can be made with 2 cups of flour.

Hope this helps!

Answer:

x = 1.5

Step-by-step explanation:

6 - 2x = 3

→ Minus 6 from both sides to isolate -2x

-2x = -3

→ Divide -2 from both sides to isolate x

x = 1.5

Answer:

The expression that could help calculate the price of the TV is;

$P - 20% of $P

Step-by-step explanation:

Here, we want to write an expression that corresponds to the price of a television set that is on sale at a price which is 20% off the regular price.

From the question, we can see that the regular price is $P

So now we are having 20% off;

This corresponds to;

20/100 * p = p/5 = 0.2p

So in the expression form, we can have;

$P - 20% of $P

Answer:

see explanation

Step-by-step explanation:

sum the parts of the ratio, 2 + 1 = 3 parts , thus

81 cm² ÷ 3 = 27 cm² ← value of 1 part of the ratio

2 parts = 2 × 27 = 54 cm²

Area of A = 54 cm² and area of B = 27 cm²

The side of the original square = [tex]\sqrt{81}[/tex] = 9 cm

The width of both rectangles is 9 cm ( width remains unchanged after cut )

Thus

Rectangle A

9 × length = 54 ( divide both sides by 9 )

length = 6 cm

Rectangle B

9 × length = 27 ( divide both sides by 9 )

length = 3 cm

Rectangle A → length = 6 cm, width = 9 cm

Rectangle B → length = 3 cm , width = 9 cm

Answer:

Rectangle A                 Rectangle B

length = 9 cm                length = 9 cm

width = 6 cm                  width = 3 cm

Step-by-step explanation:

Area of square At = 81 cm²

Square is cut into two pieces = A + B

The ration of area A to B = 2:1

Find

Rect A        Rect B

length         length

width           width

---------------------------------

first, get the side of the square = A = s²

81 = s²,      

s = √81      

s = 9 cm

since the ratio is 2:1, therefore the side can be divided into 3

9 ÷ 3 = 3 cm ----- take note of this to get the Width

Rectangle A

L = 9 cm (which is the s = 9 cm)

W = 3 cm (2 ratio) = 6 cm

Rectangle B

L = 9 cm  (which is the s = 9 cm)

W = 3 cm (1 ratio) = 3 cm

Proof:

At = A + B

81 = (9x6) + (9x3)

81 = 54 + 27

81 = 81  ----- OK

Answer:

0

Step-by-step explanation:

Common Difference = Difference between any two consecutive terms

= - 4 - (-4)

= - 4 + 4

= 0

Answer:

$26 for each child

Step-by-step explanation:

35 * 3 = 105 / 4 = 26.25

Answer:

Step-by-step explanation:

[tex]Selling \:price = 3000gh Cedis\\Profit \% = 25\%\\Cost\:price =?\\\\CP =\frac{ ( Selling\:price \times 100 )}{ ( 100 + percentage profit)} \\\\C.P = \frac{3000\times 100 }{100+25}\\\\ C.P = \frac{300000}{125} \\\\Cost\: Price = 2400gh Cedis[/tex]

Answer:

10

Step-by-step explanation:

This is a combinations problem, involving factorials.

5!/3!*2!=5*4/2=20/2=10

The different sum of the 4 coins from the list of 5 coins is an illustration of combination or selection. There are 5 different possible sums.

Given

[tex]n = 5[/tex] --- number of coins

[tex]r = 4[/tex] --- coins to be selected to calculate sum

For the sum of the coin value to be calculated, the 4 coins must be selected. This means combination.

So, we make use of:

[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]

This gives

[tex]^5C_4 = \frac{5!}{(5 - 4)!4!}[/tex]

[tex]^5C_4 = \frac{5!}{1!4!}[/tex]

Expand

[tex]^5C_4 = \frac{5*4!}{1*4!}[/tex]

[tex]^5C_4 = \frac{5}{1}[/tex]

[tex]^5C_4 = 5[/tex]

Hence, there are 5 different possible sums.

Read more about combinations at:

https://brainly.com/question/15401733

Answer:

N(t)=N∗.5t/h where n(t) is amount of substance left, N = initial amount, t = current time, and h = half-life time.h = 24 hours t= 45 hours, N = 130mg

therefore, N(t)=130∗.545/24=35.44mg

Step-by-step explanation:

N(t)=N∗.5t/h where n(t) is amount of substance left, N = initial amount, t = current time, and h = half-life time.h = 24 hours t= 45 hours, N = 130mg

therefore, N(t)=130∗.545/24=35.44mg

Answer:

≈ 130 mg

Step-by-step explanation:

This is about the half-life of the substance.

There is a formula for this kind of calculations:

N(t)= N₀*(0.5)^(t/T), where

In our case, we have:

And the calculation:

Answer: about 130 mg of substance remains after 20 hours

Answer:

2/3

Step-by-step explanation:

I am not sure

Answer:

Step-by-step explanation:

[tex]Let \:the \: unknown \: fraction \: be \: x\\\\\frac{5}{3} -x = 1\\\\\frac{5}{3}-x=1\\\\\mathrm{Subtract\:}\frac{5}{3}\mathrm{\:from\:both\:sides}\\\\\frac{5}{3}-x-\frac{5}{3}=1-\frac{5}{3}\\\\\frac{5}{3}-x-\frac{5}{3}=-x\\\\1-\frac{5}{3}=-\frac{2}{3}\\-x=-\frac{2}{3}\\\\x=\frac{2}{3}\\[/tex]

Answer:

See explanation below.

Step-by-step explanation:

A bullet shot at you will definitely hit you because of the direction it is travelling.

Your fight and flight response won't be activated either because of the speed of the event (bullet) or if you don't know how harmful a gun is (you'll remain calm/ignorant in this case)?

Try to post academic problems.

Best Regards!

Answer:

Correct option is

b. If two sides and one included angle are equal in triangles PQS and PRS, then their corresponding sides are also equal.

Step-by-step explanation:

Here, we are given the line RQ, which is divided in two equal parts by a line PS which is perpendicular to RQ.

The foot S of PS is on the line RQ.

First of all, let us do a construction here.

Join the point R with P and P with Q.

Please refer to the attached image.

Now, let us consider the triangles  PQS and PRS:

Now, Two sides and the angle included between the two triangles are equal.

So by SAS congruence we can say that [tex]\triangle PRS \cong \triangle PQS[/tex]

Therefore, the corresponding sides will also be equal.

RP = QP

RP is the distance between R and P.

QP is the distance between Q and P.

Hence, to prove that P is equidistant from R and Q, we have proved that:

b. If two sides and one included angle are equal in triangles PQS and PRS, then their corresponding sides are also equal.

Answer:

20°

Step-by-step explanation:

The measure of the inscribed angle is equal to the half of the arc it sees

Since AC is the diameter the measure of arc ABC is 180°

and since A sees arc BC and C sees the arc AB

A< + C< = 90° so angle C = 20°

Answer:

[tex]\Large \boxed{\mathrm{Option \ D}}[/tex]

Step-by-step explanation:

(6, 4)

x = 6 and y = 4

y > -1/2x + 7

Plug in the values to check if it is true.

4 > -1/2(6) + 7

4 > -3 + 7

4 > 4

This statement is false.

(6, 4) lies on the line.

Answer:

16%

Step-by-step explanation:

rental charge per year = $80

rental charge at the rate $8 per year = 8 * 12 = 96

the increased amount = 96 - 80 = 16

% = 16 / 100 = 16%

Answer:

Length = 34 feet

Breadth = 30 feet

Step-by-step explanation:

Perimeter= 128 ft

Let the breadth be = [tex]x[/tex]

Let the length be = [tex]x+4[/tex]

∴by the problem ,

2(length+breadth)= perimeter

[tex]2(x+4+x)=128\\2(2x+4)=128\\4x+8=128\\4x=128-8\\4x=120\\x=120/4\\x=30[/tex]

Therefore, length of the garden = 30+4= 34 feet

breadth of the garden = 30 feet  

Answer:

318

Step-by-step explanation:

Bob=x

Marc=x+30

Donny=3(x+30)

x+x+30+3x+90=500

5x=500-120

5x=380

x=76

Bob has x = 76

Marc has x+30=106

Donny has 3*112=318

318+106+76=500

Answer:

Step-by-step explanation:

400 km  =       x    

  6 min         9 min  

cross multiply:

6x = 400 ( 9)

x = 3600 / 6

x = 600 km

Answer:

60 tiles are used

Step-by-step explanation:

1m equals 100 cm.

5m equals 500

3m equals 300

the whole thing is 500 by 300 which when you multiply gives you

150,000. When you multiple 50 by 50 it gives you 2,500. So when you divide 150,000 by 2,500 it gives you a total of 60 tiles. HOPE THIS HELPS

Answer:

60 tiles

Step-by-step explanation:

First, I would convert cm to m to make it easier

50 cm is .5 m

Now we can find how many tiles across it takes to make one row (5m)

.5 goes into 5, 10 times

That means we need 10 tiles across to fill one row

Now we need to find how many tiles it takes to fill up a column (3m)

.5 goes into 3, 6 times

It takes 6 tiles to fill up a column

Now we know it takes 10 tiles across and 6 vertically

10x6=60

60 tiles

Answer:

A.

Step-by-step explanation:

All of those graphs represent functions. You are able to tell because they all pass the vertical line test. The vertical line test is conducted by drawing a line that goes vertically and intercepts any point of the line in question. If the function crosses the vertical line twice, it is not a function. If it only intercepts once, it is a function. In this case, every graph is a function because they would intercept a vertical line once.  

Answer: [tex]x=\dfrac{25}{21}[/tex]

Step-by-step explanation:

Area of parallelogram = Base x height

If two parallelograms are similar, then their corresponding sides are proportional.

That means, [tex]\dfrac{\text{Area of first parallleogram}}{\text{Area of second parallleogram}}=\dfrac{\text{height of first parallelogram}}{\text{height of second parallelogram}}[/tex]

[tex]\Rightarrow \dfrac{3x+5}{9x}=\dfrac{16}{20}\Rightarrow \dfrac{3x+5}{9x}=\dfrac{4}{5}\\\\\Rightarrow 5(3x+5)=4(9x)\\\\\Rightarrow\ 15x+25 = 36x\\\\\Rightarrow\ 36x-15x=25\\\\\Rightarrow\ 21x = 25\\\\\Rightarrow\ x=\dfrac{25}{21}[/tex]

Hence, [tex]x=\dfrac{25}{21}[/tex]

Answer:

Minimum People required = 5

Step-by-step explanation:

Total hours required to complete the work every week = 150 hrs.

Number of hours worked per week by one person = 32 hr

∴ Number of people required to complete the work per week = Total number of hrs to complete the work ÷ No of hrs work per person

∴ Number of people = 150 ÷ 32

∴ Number of people = 4.6875

This is the minimum number of people. But no of people cannot be a fraction.

Thus, rounding the number to next integer.

∴ Smallest number of people needed to complete the work = 5

Answer:

4x^2−2

Step-by-step explanation:

Let's simplify step-by-step.

7x^2−2−3x^2

=7x^2+(−2)+(−3x^2)

Combine Like Terms:

=7x^2(+−2)+(−3x^2)

=(7x^2+(−3x^2))+(−2)

=4x^2+−2

Answer:

=4x2−2

Answer:

2

Step-by-step explanation:

3x^2

The coefficient is 3

The variable is x

The exponent is 2