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Ratling [72]
3 years ago
5

Solve x and y simultaneously if:

Mathematics
1 answer:
Solnce55 [7]3 years ago
5 0

Answer:

make Y the subject in eqn........ 1

y + 7 = 2x

y = 2x - 7...........eqn 3

put y = 2x - 7 into eqn 2

x² - xy + 3y² = 15

x² - x(2x - 7) + 3(2x - 7)(2x - 7) = 15

x² - 2x² + 7x + 3(4x² + 14x -14x + 21) = 15

x² - 2x² + 7x + 12x² + 42x - 42x + 63 = 15

x² - 2x² + 7x + 12x² + 63 = 15

x² - 2x² + 12x² + 7x + 63 = 15

11x² + 7x + 63 - 15 = 0

11x² + 7x + 48 = 0

11x² + 7x = - 48

11x²/11 + 7x/11 = - 48/11

x² + 7x

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GEOMETRY HELP!!
Vlada [557]

Answer:

0

Step-by-step explanation:

To find the coordinate of the midpoint of segment QB, first, find the distance from Q to B.

QB = |4 - 8| = |-4| = 4

The coordinate of the midpoint of QB would be at ½ the distance of QB (½*4 = 2).

Therefore, coordinate of the midpoint of QB = the coordinate of Q + 2 = 4 + 2 = 6

OR

Coordinate of B - 2 = 8 - 2 = 6

Coordinate of the midpoint of QB = 6

Coordinate of W = -8

Coordinate of A = 0

distance from W to A (WA) = |-8 - 0| = |-8| = 8

The coordinate of the midpoint of WA would be at ½ the distance of WA = ½*8 = 4.

Therefore, coordinate of the midpoint of WA = the coordinate of W + 4 = -8 + 4 = -4

Or

Coordinate of A - 4 = 0 - 4 = -4

Coordinate of the midpoint of WA = -4

Now, let's find the midpoint between the two new coordinates we have found, which are -4 and 4

Distance of the segment formed by coordinate -4 and 4 = |-4 - 4| = |-8| = 8

Midpoint = ½*8 = 4

Coordinate of the midpoint = -4 + 4 = 0

Or

4 - 4 = 0

5 0
4 years ago
Which of the following is an equation of a line parallel to 2x-y=-1?
Simora [160]

Although you didn't provide a list of options to choose from, I hope my explanation will help you  work this out with ease. :)

This equation is in a form known as "standard form." ax+by=c Standard form is commonly used, however for comparing slopes, there is a more efficient equation to use.

Point-slope form (y=mx+b) allows lines' slopes (y) and y-intercepts (b) to be quickly compared and contrasted. Let's put the equation into this form.

2x-y=-1

-2x      -2x

-y = -1 - 2x

*-1      *-1

y= 1 + 2x

Switch pieces around

y= 2x + 1

The slope is 2, the y intercept is 1.

<h2><u>Any line that rises 2 units up for every one unit right and that crosses over the vertical axis at any point other than 1 is your answer.</u></h2>

<u />

3 0
3 years ago
[(25-11)+(15-9)]÷5 numerical expression ;)
Mrrafil [7]

Answer: 100

<u>Step-by-step explanation:</u>

[(25 - 11) + (15 - 9)] * 5

=[    14      +      6    ] * 5

=             20             * 5

=                     100

5 0
4 years ago
PLEASE ANSWER QUICKLY Which expression represents the inverse of the matrix below?
Andre45 [30]

Answer:D

Step-by-step explanation:

7 0
3 years ago
Explain how you can use a model to find 6×17
Ivan
It's 102 I don't how you can use a model though
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3 years ago
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