Solve the system using the substitution method.
2x+y=7
x=3y
Demonstrate how you substituted to write an equation in one variable.

Answer:

Step-by-step explanation:

the quadratic expression is

2x^2+9x-7

this is the only one

Answer:

2x^2+9x-7

Step-by-step explanation:

No.of sides=4

sum of angle of quadrilateral

=(n-2)*180°

=(4-2)*180°

=2*180°

=360°

Answer:

x=20

Step-by-step explanation:

x+2x+x+10=90

4x+10=90

4x=90-10

4x=80

x=80/4

x=20

Answer:

19.7%

Step-by-step explanation:

Given that,

In 2000, the world population was 6.1 billion.

In 2015, the world population was 7.3 billion.

We need to find the percentage increase in population. The percent increase in this case is given by :

[tex]\%=\dfrac{7.3-6.1}{6.1}\times 100\\\\=19.67\%\\\\=19.7\%[/tex]

So, the increase in population is 19.7%.

Answer:

A change from 64 to 80 represents a positive change (increase) of 25%

Step-by-step explanation:

Answer:

1.25*10-3m^3

Step-by-step explanation:

1kg petrol has density of 800kg/m3 find its volume in cm 3

Given data

mass m= 1kg

density = 800kg/m3

Required

The volume v

We know that

density= mass/volume

so

Volume= mass/density

substute

Volume= 1/800

volume=1.25*10-3m^3

Hence the volume is 1.25*10-3m^3

Answer:

B

Step-by-step explanation:B

Answer:

the answer to this question is B

Answer:

x=1120-d

Step-by-step explanation:

Answer:

x = 1120 - d

Step-by-step explanation:

Hi there!

We can simplify this using orders of operations.

First, subtract 125 from both sides to get x + d = 1120.

To isolate x, just subtract d from both sides.

If you give me a value for d, i can solve the full problem.

I hope this helps!

Answer:the population of brook trout

Step-by-step explanation:

Answer:

It’s D bro

Step-by-step explanation:

I’m doing the exact test rn it’s d trust

Answer:

C or D, but mostly D

Step-by-step explanation:

It's either C or D because I know the intercepts are 0 and 18. It says where X is the width so My final Answer would be D

Answer:

table b

Step-by-step explanation:

in order for it to be a function the x values cannot repeat therefore the answer is table b

Answer:

See below

Step-by-step explanation:

[tex]\frac{1}{1-cos A} - \frac{1}{1+cos A} =2 cosec A cot A \\ \\

L. H. S.= \frac{1}{1-cos A} - \frac{1}{1+cos A} \\ \\ = \frac{1+cos A - (1 - cos A)}{(1-cos A)(1+cos A)}\\ \\

= \frac{1+cos A - 1 + cos A}{1-cos^{2} A}\\ \\

= \frac{2cos A }{sin^{2} A}\\ \\

=2 .\frac{1}{sin A}.\frac{cos A }{sin A}.\\ \\ = 2.cosec \: A.cot \: A \\ \\ =

R.H.S[/tex]

Answer:

21 years

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

Step-by-step explanation:

you can use the app photo math or mathaway. its help alot the app also explains the work

Answer:

7/9 < 5/6

Step-by-step explanation:

The denominator is the common factor of the denominators

That is 54

So we have

7/9 * 6/6 = 42/54

5/6 * 9/9 = 45/54

So, the relation we have is that;

7/9 < 5/6

Answer:

4 hours

Step-by-step explanation:

Answer:

because all the numbers used are whole numbers and as a result will appear clearly on a graph. if there were decimals you would need to estimate and the answer would not be accurate

Answer:

∠CAD = 44⁰

∠ACD = 44⁰

∠ACB =  136⁰

∠ABC = 22⁰

Step-by-step explanation:

To calculate m∠CAD;

Line AD = Line DC,

thus ∠CAD = ∠ACD = ¹/₂(180 - 92°) [sum of angles in a triangle.]

       ∠CAD =  ¹/₂ x 88 = 44⁰

Also, ∠ACD = 44⁰

To calculate  m∠ACB;

∠ACB = 180 - ∠ACD [Sum of angles on a straight line]

∠ACB = 180 - 44

∠ACB =  136⁰

To calculate m∠ABC;

Line CB = Line CA

Thus, ∠ABC = ∠CAB = ¹/₂(180 - ∠ACB) [sum of angles in a triangle.]

∠ABC =  ¹/₂(180 - 136)

∠ABC =  ¹/₂ x 44

∠ABC = 22⁰

Answer:

Well if you want us to add those, then 28

If you want us to multiply, then 720

Step-by-step explanation:

I think 28 would be a more reasonable answer-

Answer:

1 7 13 91 prime factors in ascending order

Answer:

The possible values for ∠V is 81.2° and 98.8°

Step-by-step explanation:

In ΔUVW, v = 8.1 cm, u = 7.6 cm and ∠U=68°. Find all possible values of ∠V, to the nearest 10th of a degree.

We solve the above question using Sine rule

Sine rule

= u/sin U = v/sin V

In ΔUVW, v = 8.1 cm, u = 7.6 cm and ∠U=68°

Hence:

7.6/sin 68° = 8.1/sin V

Cross Multiply

7.6 × sin V = sin 68° × 8.1

sin V = sin 68° × 8.1/7.6

V = arc sin ( sin 68° × 8.1/7.6)

V = arc sin (0.99)

V = 81.18°

Another value for V = 180° - 81.18°

= 98.82°

Therefore, the possible values for ∠V approximately to the nearest tenth of a degree is 81.2° and 98.8°

Answer:

rational numbers: 4/8, -0.5, 0.333, 0.41, -4/6, 0.48, 0.1, 0.75, 7/8, 1/3, 0.97, √16/9, 0.21, 27/4 , 4.5, -6/7, 0.3

Step-by-step explanation:

In mathematics, a rational number is a number such as -3/7 that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Every integer is a rational number: for example, 5 = 5/1.

In mathematics, a rational number is a number such as -3/7 that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Every integer is a rational number: for example, 5 = 5/1. Wikipedia

Symbol: symbol ℚ matematica.pt

Answer:

$40,000

Step-by-step explanation:

2.5x+20,000=120,000

120,000-20,000=100,000

100,000/2.5=40,000

Answer:

D

Step-by-step explanation:

Question:On Saturdays. Eve earns $14. per hour for yard work and charges an extra amount for supplies/gas money to get there. Look at the table. Choose the linear function f Eve can use to determine her pay, where x is in hours and f(x) is her pay in dollars.

Answer: The answer would be D because she gets payed $14 and hour so you would plug the hours she work into the letter x.

Answer:

I believe the answer is O2

Answer:

A. Correct

B. Incorrect

C. Incorrect

D. Incorrect

Step-by-step explanation:

B, C, and D are compounds rather than elements