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eimsori [14]
2 years ago
12

Someone please explain this step by step:

Mathematics
1 answer:
Volgvan2 years ago
3 0

Answer:

  13

Step-by-step explanation:

Perhaps the most straightforward way to find the value of the given function is to first solve the equations for x and y. The results can be substituted into your expression to find the value you want.

__

<h3>solving the system</h3>

We notice the y-coefficients are opposites, so we can eliminate the y-variable by adding the equations.

  (2x -y) +(x +y) = (3) +(1)

  3x = 4 . . . . . . simplify

  x = 4/3 . . . . . divide by 3

The value of y can be found from the second equation:

  4/3 +y = 1 . . . . substitute for x

  y = -1/3 . . . . . . subtract 4/3

<h3>expression value</h3>

The value of 8x-7y is found by substituting the x- and y-values into this expression:

  8(4/3) -7(-1/3) = 32/3 +7/3 = 39/3 = 13

The value of 8x-7y is 13.

_____

<em>Additional comment</em>

You can also work out what combination of the two equations will give 8x -7y. That turns out to be 5 times the first minus 2 times the second:

  5(2x -y) -2(x +y) = 5(3) -2(1)

  10x -5y -2x -2y = 15 -2

  8x -7y = 13

__

The coefficients 5 and -2 are found by solving the system of equations ...

  a(2x -y) +b(x +y) ≡ 8x -7y   ⇒   {2a +b = 8, -a +b = -7}

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The rational number -13/-5 lies to the right of zero on the number true or false​.
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Answer:

true

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3 years ago
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The cost C (in dollars) of making n watches is represented by C=15n 85. How many watches are made when the cost is $385?
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3 years ago
Find the solutions to x2 = 24.<br> O A. x = +216<br> O B. x = 16.6<br> O C. x= 46<br> O D. x = +62
babymother [125]

Answer:

x =±2 sqrt(6)

Step-by-step explanation:

x^2 = 24

Take the square root of each side

sqrt(x^2) = sqrt(24)

x = ±sqrt(4*6)

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5 0
3 years ago
2) -4x – 6(3x + 4) = -4 + 8(1 - x)
likoan [24]

Answer:

x=-2

Step-by-step explanation:

-4x – 6(3x + 4) = -4 + 8(1 - x)

Distribute

-4x – 18x  -24 = -4 + 8 -8x

Combine like terms

-22x -24 = 4-8x

Add 22x to each side

-22x+22x -24 = 4-8x+22x

-24 =4+14x

Subtract 4 from each side

-24-4 = 4+14x-4

-28 = 14x

Divide each side by 14

-28/14 =14/14

-2 =x

5 0
3 years ago
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5x + 2y =17 <br> 3x +2y=13
tresset_1 [31]
1. Y= -5/2x + 17/2 (slope intercept form)
2. Y= -3/2x + 13/2 (slope intercept form)
4 0
2 years ago
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