If two equations are 3x + 2y = 14; 5x + 3y = 12, then the value of
5x – y is

Answer:

40/9

Step-by-step explanation:

Use the work formula, [tex]\frac{1}{A}[/tex] + [tex]\frac{1}{B}[/tex] = [tex]\frac{1}{T}[/tex], where A is the amount of time it takes one person, B is the amount of time it takes another person, and T is the time it takes for them to work together.

Plug in the times for David and Alex alone:

[tex]\frac{1}{10}[/tex] + [tex]\frac{1}{8}[/tex] = [tex]\frac{1}{T}[/tex]

Find the least common denominator, which is 40.

[tex]\frac{4}{40}[/tex] + [tex]\frac{5}{40}[/tex] = [tex]\frac{1}{T}[/tex]

[tex]\frac{9}{40}[/tex] = [tex]\frac{1}{T}[/tex]

Cross multiply and solve for T:

9T = 40

T = 40/9

So, if they worked together, it would take them 40/9 hours

Answer:

40/9

Step-by-step explanation:

just helped my sister with this question.

Answer:

i think it will weigh 8 ounces

Step-by-step explanation:

if one can plus it is equal to 2 itll will be balenced

Answer:

58.50

Step-by-step explanation:

Multiply 50 and .17 which equals 8.5 then add that to 50.

The amount of money in the account in December with a rate of 17% of the initial amount of $50 is $58.5.

The amount of something is expressed as if it is a part of the total which is a hundred. The ratio can be expressed as a fraction of 100. The word percent means per 100. It is represented by the symbol ‘%’.

A teenager puts $50 into an investment account in January.

Let, he deposited on first January.

If by December the balance in the account increases by 17%,

Let the amount by the 31 first of December will be

Then the amount will be given as

[tex]A = P (1 + \dfrac{r}{100})^t[/tex]

P = $50

r = 17%

t = 1

Then we have

[tex]\rm A = 50(1 + \dfrac{17}{100})^1\\\\A = 50(1 + 0.17)\\\\A = 50 * 1.17 \\\\A = 58.5[/tex]

More about the percentage link is given below.

https://brainly.com/question/8011401

Answer:

51.2 miles

Step-by-step explanation:

25.6 x 2= 51.2

First determine 15% of 340. Multiple 15 (as decimal) by 340.

0.15 x 340 = 51

Find the total amount she earns by adding these values.

51 + 340 = 391

Therefore, she will make $391.

the awenser is three

hundred and fifty five dolars

Answer:

  (B)  a = $0.50, b = $0.25

Step-by-step explanation:

Answer choice B is the only one in which an apple costs twice as much as a banana.

__

It helps to see if the answer choices match the requirements of the problem statement.

Answer:

64

Step-by-step explanation:

100-6^2

6^2=36

100-36=64

Hope this helps :)

Answer:

8 cm

Step-by-step explanation:

Th smaller rectangle is a scaled down version of the bigger rectangle. The smaller rectangle is 1/2 the size of the large one.

So we will multiply 4 by 2 to get 8 cm

Your correct answer is 8 cm :)

Hope this helps!

Please rate and mark brainliest!!

Have a great day!!

Answer:

the ratio of rectangle 1 the same with rectangle 2 so as you see in the photo the area of rectangle 2 equal 4×2 which we find it obviously of similar ratio

Answer:

x=11

x=−5

Step-by-step explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :  6*x+55-(x^2)=0

 -x2+6x+55  =0

According to the Quadratic Formula,  x  , the solution for   Ax2+Bx+C  = 0  , where  A, B  and  C  are numbers, often called coefficients, is given by :

           - B  ±  √ B2-4AC

 x =   ————————

                     2A

 In our case,  A   =     -1

                     B   =    6

                     C   =   55

Accordingly,  B2  -  4AC   =

                    36 - (-220) =

                    256

Applying the quadratic formula :

              -6 ± √ 256

  x  =    ——————

                     -2

Can  √ 256 be simplified ?

Yes!   The prime factorization of  256   is

  2•2•2•2•2•2•2•2  

To be able to remove something from under the radical, there have to be  2  instances of it (because we are taking a square i.e. second root).

√ 256   =  √ 2•2•2•2•2•2•2•2   =2•2•2•2•√ 1   =

               ±  16 • √ 1   =

               ±  16

So now we are looking at:

          x  =  ( -6 ± 16) / -2

Two real solutions:

x =(-6+√256)/-2=3-8= -5.000

or:

x =(-6-√256)/-2=3+8= 11.000

Answer:

(x-3)^2 =64

x=3 plus or minus 8

Step-by-step explanation:

I got it right on khan

Answer:

54 ft squared

Step-by-step explanation:

To find surface area l*w

9*6=54 ft squared

Answer:

74

Step-by-step explanation:

Answer:

D=(6T)+(9R)

Step-by-step explanation:

Since she runs 6mph and bikes 9mph, the distance she covers can be described as D=(6T)+(9R).

Answer:

130% increase

Step-by-step explanation:

Answer:

1.A

-$92

-$212

1.B

To solve this you set up the equation:  x(8) +12 =y. In this equation x=, the number of paintbrushes and y=, the total cost of the purchase. If you plug in the number of paintbrushes that are being bought you should be able to get your Y(total cost).

Hope this helped!

Answer:

a. Check Mark

b. Check Mark

c. No Check Mark

d. No Check Mark

e. No Check Mark

Step-by-step explanation:

1 hour = 60 minutes

1/4 X 60 min = 15

9 pages every 15 minutes

9 X 4 = 36

36 pages in an hour

Answer: x = 52.1 degrees

Step-by-step explanation:

The tangent of an angle is the opposite side divided by the adjacent side.

Therefore, tan(x) = 45/35.

We can find thte value of x by doing the arc tangent of 45/35, which makes x about 52.1 degrees.

Answer:

1.[tex]\:\left(-\infty \:,\:1\right)[/tex]
2.[tex]\:[11,\:\infty \:)[/tex]

Step-by-step explanation:

Given the following questions:

[tex]x-5 < -4[/tex]
[tex]-7x+6\leq-71[/tex]

To find the answer we solve as if it is a two-step equation where we add/subtract on both sides.

Question one:
[tex]x-5 < -4[/tex]
[tex]-5+5=0[/tex]
[tex]-4+5=1[/tex]
[tex]x < 1[/tex]
[tex]\:\left(-\infty \:,\:1\right)[/tex]

Question two:
[tex]-7x+6\leq-71[/tex]
[tex]6-6=0[/tex]
[tex]-71+-6=-77[/tex]
[tex]-7x\leq-77[/tex]
[tex]-7x\div-7=x[/tex]
[tex]-77\div-7=11[/tex]
[tex]x\leq11[/tex]
[tex]\:[11,\:\infty \:)[/tex]

Which means your answers are "(-∞, 1) and [11, ∞)."

Hope this helps.

Answer:

E = 20h, she earns $300 for 15 hours

It is B :)

Step-by-step explanation:

Answer: If you substitute the x for 3, and multiply 4 times 3, you’ll get 12 and then you subtract 9 from 12 and then you’ll get 3. I’m pretty sure y=3

Step-by-step explanation:

Answer:

25/16

Step-by-step explanation:

(4/5)^-2

Use Negative Power Rule: x^-a = 1/x^a

1/(4/5)^2

Use Division Distributive Property: (x/y)^a = x^a/y^a

1/16/5^2

1/16/25

25/16

Please mark me the brainliest!?!

Answer:

Slope (m) = tanθ

=tan60

=√3

Hence the slope is √3

I think it will help you

Answer:

70

Step-by-step explanation:

all angles in a triangle add up to 180

if two sides are equal their angles are equal

180-40

140÷2

70

Answer:

A.) x < 3

Step-by-step explanation:

I jus got 100% on the quiz.

Answer:

the highest common factor of 25 and 35 is 5

so,

5(5y-7z) is the factorise form of 25y-35z

Step-by-step explanation:

hope this helps you!!