Rewrite the equation by completing the square.
x^2-x-20=0
(x+ ? )^2= ?

please help me

Answer:

[tex] \rm\cos({600}^{ \circ} ) =-1/2 [/tex]

Step-by-step explanation:

we would like to solve the following using double-angle formula:

[tex] \displaystyle \cos( {600}^{ \circ} ) [/tex]

there're 4 double Angle formulas of cos function which are given by:

[tex] \displaystyle \cos(2 \theta) = \begin{cases} i)\cos^{2} ( \theta) - { \sin}^{2}( \theta) \\ii) 2 { \cos}^{2}( \theta) - 1 \\iii) 1 - { \sin}^{2} \theta \\ iv)\dfrac{1 - { \tan}^{2} \theta}{1 + { \tan}^{2} \theta } \end{cases}[/tex]

since the question doesn't allude which one we need to utilize utilize so I would like to apply the second one, therefore

step-1: assign variables

to do so rewrite the given function:

[tex] \displaystyle \cos( {2(300)}^{ \circ} ) [/tex]

so,

Step-2: substitute:

[tex] \rm\cos(2 \cdot {300}^{ \circ} ) = 2 \cos ^{2} {300}^{ \circ} - 1[/tex]

recall unit circle thus cos300 is ½:

[tex] \rm\cos(2 \cdot {300}^{ \circ} ) = 2 \left( \dfrac{1}{2} \right)^2 - 1[/tex]

simplify square:

[tex] \rm\cos(2 \cdot {300}^{ \circ} ) = 2\cdot \dfrac{1}{4} - 1[/tex]

reduce fraction:

[tex] \rm\cos(2 \cdot {300}^{ \circ} ) = \dfrac{1}{2} - 1[/tex]

simplify substraction and hence,

[tex] \rm\cos({600}^{ \circ} ) = \boxed{-\frac{1}{2}}[/tex]

Using Pythagorean triplet

[tex]\\ \sf\longmapsto AB^2=AC^2-BC^2[/tex]

[tex]\\ \sf\longmapsto AB^2=4^2-3^2[/tex]

[tex]\\ \sf\longmapsto AB^2=16-9[/tex]

[tex]\\ \sf\longmapsto AB^2=7[/tex]

[tex]\\ \sf\longmapsto AB=\sqrt{7}[/tex]

[tex]\\ \sf\longmapsto Velocity=\dfrac{Displacement}{Time}[/tex]

[tex]\\ \sf\longmapsto Velocity=\dfrac{\sqrt{7}}{35}[/tex]

[tex]\\ \sf\longmapsto Velocity=\dfrac{2.6}{35}[/tex]

[tex]\\ \sf\longmapsto Velocity=0.07m/s[/tex]

Answer:

Step-by-step explanation:

We know, for square

[tex](side)^2=(Area)\\=>X^2=8\\[/tex]

∴[tex]X=2\sqrt{2}[/tex] unit

[tex]Now, Side=3X[/tex]

[tex]Then,Area=(3X)^2=(3*2\sqrt{2} )^2=(6\sqrt{2} )^2=72 sq. unit[/tex]

hope you have understood this...

pls mark my answer as the brainliest

The area of square of side 3X is 72 square unit.

The square is a 4 sided figure, each side of the square is equal and make a right angle.

The area of square having sided a unit can be given by a² square unit.

Given that,

Area of square having side X is 8.

Since, formula for area of square having side X is X².

Implies that,

X² = 8

X = 2√2

The area of square having side 3X
side =3 × 2√2

side = 6√2

The area of square = (6√2)²

                                = 36 x 2

                                = 72

The area of square is 72 square unit.

To know more about Square on:

https://brainly.com/question/28776767

#SPJ2

Answer:

Step-by-step explanation:

Solve for a:

Answer:

x= -1

Step-by-step explanation:

Since x= 5 is a vertical line, the unknown line would also be a vertical line with an equation of x=___ as they are parallel to each other.

Given that the line passes through (-1, 2), the equation of the line is x= -1.

Parallel lines have the same slope and will never meet.

Answer:

The answer to your question would be x=12. Equation is worked out below

Step-by-step explanation:

5 /2 x−7= 3 /4 x+14

5 /2 x-3/4x − 7 =  3 /4 x-3/4x +14

7/ 4 x−7=14

7 /4 x−7+7=14+7

7/ 4 x=21

do the opposite of 7/4x (division)

7/4 / 7/4x = 21 / 7/4

4/7 / 7/4x (cross each other out) = 21 / 4/7

x=12

Answer:

[tex] \frac{5}{2}x - 7 = \frac{3}{4} x + 14 \\ \frac{5}{2} x - \frac{3}{4} x = 14 + 7 \\ \frac{7}{4} x = 21 \\ x = \frac{21 \times 4}{7} \\ x = 12[/tex]

I hope I helped you^_^

Answer:

10t+2

Step-by-step explanation:

2-5t+8+5t-8

10t+2

Answer:

D. All three chose a valid first step toward solving the equation.

Step-by-step explanation:

Aaron, Blaine, and Cruz are solving the equation 4/7 (7 − n) = −1. Aaron started his solution by multiplying both sides of the equation by 7/4 . Blaine started by using the distributive property to multiply 4/7 by both 7 and −n. Cruz started by dividing both sides of the equation by 4/7 .

Which of the following is true?

A. Blaine and Cruz made an error in picking their first steps.

B. Cruz made an error in picking his first step.

C. All three made an error because the right side equals -1.

D. All three chose a valid first step toward solving the equation.

Given:

4/7(7 - n) = -1

Aaron:

4/7(7 - n) = -1

Multiple both sides by 7/4

4/7(7 - n) * 7/4 = -1 * 7/4

7 - n = -7/4

- n = -7/4 - 7

- n = (-7-28)/4

- n = -35/4

n = 35/4

Blaine:

4/7(7 - n) = -1

4/7(7 - n) × 7 = -1 × 7

4(7 - n) = -7

28 - 4n = -7

-4n = -7 - 28

- 4n = - 35

n = -35/-4

n = 35/4

Cruz:

4/7(7 - n) = -1

Divide both sides by 4/7

4/7(7 - n) ÷ 4/7 = -1 ÷ 4/7

4/7(7 - n) × 7/4 = -1 × 7/4

7 - n = -7/4

- n = (-7-28)/4

- n = -35/4

n = 35/4

D. All three chose a valid first step toward solving the equation.

Answer:

D-All three chose a valid first step toward solving the equation.

Step-by-step explanation:

Hope I Helped

Answer:

option c is the correct answer (l=1 cm and w=42cm)

Step-by-step explanation:

length(l) = 1.00cm

width(w)= 42.00 cm

ACCORDING TO FORMULA

Area of rectangle = l×w

=1 cm × 42 cm

= 42cm^2

Answer:

11,968

Step-by-step explanation:

I'm not sure, but I think its 11,968

Answer: A

Step-by-step explanation: A function is when every domain (x value) corresponds to one range (y value) so that it passes the vertical line test

Answer:

C

Step-by-step explanation:

[tex] \frac{x}{3} [/tex]

Answer:

Step-by-step explanation:

The rate of change for the interval between x = 2 and x = 6 is simply asking you for the slope of the line that connects these 2 coordinates. If you were in calculus, you could find the instantaneous slope at any point on this parabola, but you're not quite that lucky yet, so we will go about it the only way we can:

by finding the slope. Remember, that slope is the same thing as rate of change.

[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex] and filling in:

[tex]m=\frac{14-2}{6-2}=\frac{12}{4}=3[/tex]

Answer:

[tex]f(x) = 3x - 5[/tex]

For a zero, f(x) = 0:

[tex]{ \tt{0 = 3x - 5}} \\ { \tt{x = \frac{5}{3} }}[/tex]

Answer:

He ate 1/12 of the pizza

Step-by-step explanation:

Divide the pizza by 4 to get the share each friend got

1/4

Then Binli ate 1/3 of his share

1/4 * 1/3 = 1/12

He ate 1/12 of the pizza

Answer:

$119.335

Step-by-step explanation:

8.23 per hour

14h 30 mins = 14.5 hrs

8.23*14.5 = 119.335

Answer:

238.67

Step-by-step explanation:

Answer:

perimeter=40m

Step-by-step explanation:

PERIMETER=(AREA ROOT)*4

                   =10*4=40m

Answer:

d=2

Step-by-step explanation:

We are given equation:

sqrt(4y-3)=d-y

Squaring both sides gives:

4y-3=(d-y)^2

Applying the identity (x+y)^2=x^2+2xy+y^2 on right:

4y-3=d^2-2dy+y^2

Now let's y=7:

4(7)-3=d^2-2d(7)+(7)^2

Simplify:

25=d^2-14d+49

Subtract 25 on both sides:

0=d^2-14d+24

Factor left:

0=(d-12)(d-2) since -2+-12=-14 and -2(-12)=24

This gives d=12 or d=2.

The d that makes d-y or I mean d-7 negative will give us y=7 as extraneous

Since 2-7 is -5, then d=2 is what we are looking for.

Check:

sqrt(4y-3)=d-y

Set d=2: sqrt(4y-3)=2-y

Now solve for y:

Square both sides: 4y-3=4-4y+y^2

Subtract 4y and 3 on both sides: 0=7-8y+y^2

Reorder right side: 0=y^2-8y+7

Factor: 0=(y-7)(y-1) since -7+-1=-8 and -7(-1)=7

This gives y=7 or y=1.

Plugging in y=7 for a check to this equation gives:

sqrt(4×7-3)=2-7

Sqrt(25)=-5

5=-5 which is not true which is what we wanted

Answer:

1/6 <x

Step-by-step explanation:

-2(8 x - 4) < 2x + 5

distribute

-16x+8 < 2x+5

Add 16x to each side

-16x+16+8 < 2x+16x+5

8<18x+5

Subtract 5 from each side

8-5 < 18x+5-5

3<18x

Divide by 18

3/18 <18x/18

1/6 <x

I think it migth be the first one

give me brainlieSt

it is 1/6

Answer:

1.-4,-1,1,6

2.by substituting the values given, we get

32-|15+8|

32-|23|

32-23=9

3.-15+7=8

4..27-(-12)=27+12=39

5.-6.05+(-2.1)

-6.05-2.1=-8.15

6.-3/4-(-2/5)

-3/4+2/5

=-7/20

7.-9(-12)

=108

8.(3.8)(-4.1)

-15.58

9.(-8x)(-2y)+(-3y)(z)

(16xy)+(-3zy)

(16xy)-(3zy)

10.by substituting the value given,we get

2.5*(-3.2)+5

-8+5

-3

so here are the answers,mark as brainliest if u find it useful

thank you

Hi! I'm happy to help!

To solve this, we need to turn all the kilograms into pounds. We know that to turn 1 kg into a pound, you multiply the amount of kilograms by 2.2.

Knowing this, we can multiply our 31 kilograms by 2.2.

31×2.2=68.2

This means that 31 kilograms is equal to 68.2 pounds.

I hope this was helpful, keep learning! :D

Answer: 1. 41.67years

2. £9.21

3. 7.75cm

Step-by-step explanation:

1. At a party, thirty people have an age of 30, forty have an age of 40 and fifty an age of fifty. What is their average age?

Total ages = (30 × 30) + (40 × 40) + (50 × 50) = 900 + 1600 + 2500 = 5000

Total number of people = 30 + 40 + 50 = 120

Average age = Total ages / Total number of people

= 5000/120

= 41.67 years

2. In a hardware shop, there are 30 spanners costing £6, 55 hacksaws costings £9 and 10 soldering irons costings £20. What is the average cost per item?

Total cost of items = (30 × £6) + (55 × £9) + (10 × £20) = £180 + £495 + £200 = £875

Total number of items = 30 + 55 + 10 = 95

Average cost per item = £875/95 = £9.21

3. Using this frequency table, find the average height of a turnip.

Height (to nearest cm)

6cm 7cm 8cm 9cm 10cm

Frequency: 3 8 12 4 1

Total height = (3 × 6cm) + (8 × 7cm) + (12 × 8cm) + (4 × 9cm) + (1 × 10cm) = 18cm + 57cm + 96cm + 36cm + 10cm = 217cm

Total number of turnips = 3 + 8 + 12 + 4 + 1 = 28

Average height = 217cm/28 = 7.75cm

Answer:

6^2 = 36

Step-by-step explanation:

10^2 = 10 * 10 = 100

4^3 = 4 * 4 * 4 = 64

10^2 - 4^3= 100 - 64 = 36 = 6^2

Hi there!  

»»————-　★　————-««

I believe your answer is:  

[tex]6^2[/tex]

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{Calculating the answer...}}\\\\10^2 - 4^3\\---------------\\\rightarrow 10^2 = 100\\\\\rightarrow 4^3 = 64\\\\\rightarrow 100 - 64 = \boxed{36}\\\\\text{Since we know that '36' is a perfect square, we can rewrite our answer as: } \boxed{6^2}[/tex]

⸻⸻⸻⸻

»»————-　★　————-««  

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

Answer:

y = 1/2x + 5/2

Step-by-step explanation:

y = 1/2x + b

5 = 1/2(5) + b

5 = 5/2 + b

5/2 = b

Answer:

A

Step-by-step explanation:

No solution because the line will never intersect each other (cuz the gradient is the same)

Answer:

(-5,2)

Step-by-step explanation:

Answer:

(5 , 2)

Step-by-step explanation:

F(-5 , 2)

After reflection F'(5 , 2)

The rule for reflection over y-axis is

Original point(x , y)   :  After reflection:  (-x,y)

x-coordinate will change its sign and y-coordinate remains same

Answer: A

Therefore, the answer is A.

Answer:

75 and 75

Step-by-step explanation:

Answer:

Hello,

Step-by-step explanation:

2 solutions:

Answer:

1.5 per hour

Step-by-step explanation: