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3 years ago

The sum of two numbers is 3.1. Twice the large number is 7 more than 3 times the smaller number. What are the numbers?

Mathematics

1 answer:

Degger [83]3 years ago

7 0

Let the two numbers be x and y where x is greater than y.

So;

x + y = 3.1 ... (i)

2x - 3y = 7 ... (ii)

This forms a set of simultaneous equations (i) and (ii)

Solving the simultaneous equations by elimination;

We multiply (i) by 2 and (ii) by 1 to get:

2x + 2y = 6.2 ... (i)

2x - 3y = 7 ... (ii)

Subtracting (i) - (ii) we get;

5y = -0.8

y = -0.8/5 = -0.16

x = 3.1 - -0.16 = 3.26

The numbers are 3.26 and -0.16.

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If sales tax is 7.75%, what is the total cost of an 11$ purchase including tax?

Akimi4 [234]

Answer:

$11.8525

Step-by-step explanation:

To find the total price of purchase including sales tax, we need to add sales tax to our total. This can be done as follows: Purchase price + percentage of purchase price as according to sales tax. In the case of your problem, this takes the form of $11 + 0.0775(11). This expression is equivalent to 11.8525.

7 0

3 years ago

Read 2 more answers

Plsss help me this is due Friday:{

prisoha [69]

Answer:

1.) subtract = 1 1/3 - 3 1/2 = answer

2.) subtract = 6 3/4 - 1 1/2 = answer

3.) add = 3 1/4 + 2 1/8= answer

4.) subtract = 4 3/4 - 2 1/6 = answer

Step-by-step explanation:

5.) 3 lawns = 6 3/4 hrs

1st lawn 2 1/2 hrs

2nd lawn 1 3/4 hrs

add 2 1/2 + 1 3/4 = total

then 6 3/4 hrs - total = the amount it takes to mow the 3rd lawn

im sure u know how to add and subtract fractions is u r in middle school :)

7 0

3 years ago

Find the volume of a cylinder if the radius is 12 inches and the height is 17 inches

Alex Ar [27]

Answer:

Volume of the cylinder = $7686.72\,inches^3$

Step-by-step explanation:

Radius(r) of the cylinder= $12\,inches$

Height(h) of the cylinder= $17\,inches$

Volume of a cylinder is :

$\pi \times r^2\times h$

As,

$\pi =\dfrac{22}{7}=3.14$

Volume is:

$=3.14\times (12\times 12)\times 17\\\\=3.14\times 144 \times 17\\\\=3.14\times 2448\\\\=7686.72\,inches^3$

The volume of the cylinder is: $7686.72\,inches^3$

3 0

3 years ago

2. Mr. Lavi determined that the total cost of his son's birthday party, c, could be represented by

Tresset [83]

Answer:

41 people attended the party

Step-by-step explanation:

$1120 = 20x + 300$

$1120 - 300 = 20x$

$820 = 20x$

$x = 41$

4 0

2 years ago

The town recreation department ordered a total of 100 baseballs and bats for the summer.Baseballs cost $4.50 each and bats cost

Romashka [77]

Answer:

The town recreation department ordered 66 baseballs and 24 bats.

Step-by-step explanation:

Let the number of baseball be 'x'.

Also Let the number of bats be 'y'.

Given:

Total items bought = 100

Now we can say that;

Total items bought is equal to sum of number of baseball and number of bats.

Framing in equation form we get;

$x+y =100 \ \ \ \ equation \ 1$

Also Given:

Cost of each baseball = $4.50

Cost of each bat = $20

Total purchase = $822

Now we can say that;

Total Purchase is equal to to sum of number of baseball multiplied by Cost of each baseball and number of bats multiplied by Cost of each bat.

framing in equation form we get;

$4.5x+20y =822 \ \ \ \ equation\ 2$

Multiplying equation 1 by 4.5 we get;

$4.5(x+y) =100\times4.5\\\\4.5x+4.5y = 450 \ \ \ \ equation \ 3$

Now Subtracting equation 3 from equation 2 we get;

$(4.5x+20y)-(4.5x+4.5y) = 822-450\\\\4.5x+20y-4.5x-4.5y =372\\\\15.5y = 372$

Dividing both side by 15.5 we get;

$\frac{15.5y}{15.5}= \frac{372}{15.5}\\ \\y =24$

Substituting the value of y in equation 1 we get;

$x+y =100\\\\x+24 =100\\\\x =100-24 =66$

Hence the town recreation department ordered 66 baseballs and 24 bats.

5 0

2 years ago