MATHEMATICS MIDDLE SCHOOL

Solve for x and y
3x-7y=6

7x+3y=72

Answers

Answer 1
Answer: This is a System of Equations, so basically what we want to do is to get one of these variables to equal zero. However none of the variables are equal, 7x doesn't equal 3x and 3y is not 7y. So we need to multiply both equations in the system to make one of these variables equal.

Let's Multiply The Top One By 3
3x - 7y = 6 \n 3(3x - 7y) = 3(6) \n 9x - 21y = 18
Let's Multiply The Bottom One By 7
7x + 3y = 72 \n 7(7x + 3y) = 7(72) \n 49x + 21y = 504
Now As You Can See 21y and -21y are equal, aand by that I mean that they will equal zero once added.

Now We Solve The System
1st. Add Straight Down Ex. 9x+49x, -21y+21y, 18+504
9x - 21y = 18\n 49x + 21y = 504
Add Straight Down
58x + 0y = 522 \n 58x + 0 * y = 522 \n 58x = 522
Now we Solve For X
58x = 522 \n (58x)/(58) = (522)/(58) \n x = 9

Now We've Found X, We Need Y, and We Can Find It By Plugging In X To One of The ORIGINAL EQUATIONS.

One Of The Original Equations
3x - 7y = 6

1st. X=9, So Replace X with 9

3(9) - 7y = 6 \n 27 - 7y = 6
Solve For Y

- 7y = 6 - 27 \n - 7y = - 21 \n ( - 7y)/( - 7) = ( - 21)/( - 7) \n y = 3

Now We Test It, X=9, Y=3
3x - 7y = 6 \n 3(9) - 7(3) = 6 \n 27 - 21 = 6 \n 6 = 6
AND

7x + 3y = 72 \n 7(9) + 3(3) = 72 \n 63 + 9 = 72 \n 72 = 72
SO: ANSWER
x = 9 \n y = 3

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What is 1/10 of 3,000

Answers

1/10 of 3000 is equal to 300

Answer:

300

Step-by-step explanation:

You take your 3000 and write it down. When you are dividing numbers and fractions, you divide by the bottom and multiply by the top. Following this, we know that 1/10 is equal to divided by 10.  You now go back to that paper and look at your 3000. Divided by 10 is just moving the decimal point one to the left. that leaves you with 300.0, or 300.

A rectangle is eight inch long and its diagonal is ten inches. What's the width of the rectangle?

Answers

Diagonal = \sqrt{length^(2) + width^(2) }

10 = \sqrt{8^(2) + width^(2) }

10 = \sqrt{64 + width^(2) }

100 = 64 + width^(2)

width^(2)\n = 100 - 64

width^(2) = 36

width = √(36)

width = 6 inches

Answer:

the answer is 6 inches

Step-by-step explanation:

To find the diagonal we use the Pythagorean Theorem:

l² + w² = d² where the is d hypotenuse

8² + w² = 10²

64 + w² = 100

w² = 100 - 64

w² = 36

w = √36

w = 6

therefore the width of the rectangle is 6 inches

I hope this was helpful !!!!!!!!!

Which of the following is equivalent to (5 /k) + ((k + 3) /(k + 5)) ?A. (k +8) /(2k + 5)
B. (k + 8) /k(k + 5)
C. 5(k + 3) /k(k + 5)
E. (k^2+ 8k + 25) /k(k + 5)

Answers

(5)/(k)+(k+3)/(k+5)=(5(k+5))/(k(k+5))+(k(k+3))/(k(k+5))=(5k+25+k^2+3k)/(k(k+5))=(k^2+8k+25)/(k(k+5))\n\nAnswer:E

Answer:

E is the answer.

Step-by-step explanation:

isabella spends $4.87 on paintbrushes and paint. How many of each item does she buy? The paintbrushes cost $0.95 and the jar of paint cost $.099 each.

Answers

Isabella can buy together 5 paintbrushes ( p ) and jars of paint ( p ) : j + p = 5, She can`t buy 4 items ( because 4 * $0.99 = $3.96 < $4.87 ) and she also can`t buy 6 items ( 6 * $0.95 = $5.70 > $4.87 ). So: p = 5 - j. Another equation is: 0.95 * ( 5 - j ) + 0.99 j = 4.87, 4.75 - 0.95 j + 0.99 j = 4.87; 0.04 j = 0.12; j = 0.12 : 0.04; j = 3, p = 5 - 3 = 2. We can prove it: 0.95 * 2 + 0.99 * 3 = 1.90 + 2.97 = 4.87. Answer: Isabella buys 2 paintbrushes and 3 jars of paint.

Write an addition fact that helps you solve 16 - 9.

Answers

9+7=16 so 16-9=7 that's what helps me solve it
9+7=16 because 16-9=7

What does how many mean a math problem is it división, multiply, or subtract, add

Answers

Mean is a problem of addition and division.

What is a mean?

It is the average value of the set given.

It is calculated as:

Mean = Sum of all the values of the set given / Number of values in the set

We have,

We can consider the following set of numbers.

= 1, 2, 3, 4, 5

The mean of 1, 2, 3, 4, 5.

= (1 + 2 + 3 + 4 + 5) / 5

= 15/5

= 3

We see that,

While calculating the mean we add all the given values and divide by the number of values added.

Thus,

Mean is a problem of addition and division.

Learn more about mean here:

brainly.com/question/23263573

#SPJ2
Mean=average So add all numbers, then divide by however many numbers there are
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