find x and y. for 2x-3y=7 and -3x+y=7?

2x - 3y = 7
-3x + y = 7

Multiply the second equation by 3:
2x - 3y = 7
-9x + 3y = 21

Add the equations:
-7x = 28
x = 28/-7 = -4

Put this value back into the second equation:
-3(-4)+ y = 7
12 + y = 7
y = -5

Your solution is (-4, -5)

Lets multiply -3x+y=7 by 3, so you have
-9x+3y=21.
Then add both equations, canceling out y, giving you
-7x=28, so x=28/-7= -4.
SO, using first equation, the you know
(2*-4)-3y=7, or
-8-3y=7, or
-3y=7+8=15, so
y=15/-3= -5.
So, x=-4 and y=-5.

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RE:
find x and y. for 2x-3y=7 and -3x+y=7?
2x - 3y = 7
-3x + y = 7
find the order pair

2x - 3y = 7
-9x + 3y = 21---------ADD

- 7x = 28
x = - 4

12 + y = 7
y = - 5

x = - 4 , y = - 5

2x - 3y = 7
2x = 7 + 3y
x = (7 + 3y)/2
-3x = -3(7 + 3y)/2

-3x + y = 7
-3(7 + 3y)/2 + y = 7
(-21 - 9y)/2 + y = 7
2[(-21 - 9y)/2] + y] = 2(7)
-21 - 9y + 2y = 14
-9y + 2y = 14 + 21
-7y = 35
y = 35/-7
y = -5

2x - 3y = 7
2x - 3(-5) = 7
2x - (-15) = 7
2x = 7 - 15
2x = -8
x = -8/2
x = -4

∴ x = -4 , y = -5

2x - 3y = 7__①
-3x + y = 7__②
From equation ②,
y = 7 + 3x__③
substitute equation ③ into equation ①;
2x - 3(7 + 3x) = 7
2x - 21 - 9x = 7
-7x = 28
x = -4

substitute x = -4 into equation ③;
y = 7 + 3(-4)
y = 7 - 12
y = -5

2x-3y = -3x +y

2x +3x = y+3y

5x= 4y

y = 5/4 *x

substituting,

2x - ( 3*5/4 x) = 7

2x - 15x/4 =7

( 8x- 15x) /4 = 7

-7x = 28

x= -4

y =5x/4 =5*-4/4 = -5

2x - 3y = 7
-9x + 3y = 21 (multiplying equation 2 by 3)
-7x = 28 (adding the two equations together)
x = -4 (dividing by the coefficient of x)

2(-4) - 3y = 7 (substituting for x)
-8 - 3y = 7 (multiplying)
-3y = 15 (adding 8 to both sides of your equation)
y = -5 (dividing by the coefficient of y)

-3(-4) + (-5) = 7 (checking your solution in equation 2)
12 - 5 = 7
7 = 7

2x - 3y = 7
y = 7 + 3x

substitute y into 2x - 3y = 7
2x - 3(7+3x) = 7

2x - 21 - 9x = 7
x = -4

y = 7 + 3(-4)
y = -5

2x-3y=7...eq(1), -3x+y=7...eq(2). therefore x=3y/2+7/2....eq 1, sub it into eq 2, -3(3y/2+7/2) + y=7 ...eq2,, where -2y=28 , and y= -14, and x =7/3