Respuesta :

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EQUATION 1: x-y=12
EQUATION 2: 3x+y=4

STEP 1:
solve for one variable in equation 1

x - y= 12
add y to both sides

x= 12 + y


STEP 2:
use x value from step 1 and substitute in equation 2

3x + y= 4

3(12 + y) + y= 4
multiply 3 by parentheses

(3*12) + (3*y) + y= 4
multiply inside parentheses

36 + 3y + y= 4
combine like terms

36 + 4y= 4
subtract 36 from both sides

4y= -32
divide both sides by 4

y= -8


STEP 3:
substitute y value from step 2 into either equation

x - y= 12
x - (-8)= 12
x + 8= 12
subtract 8 from both sides
x= 4


CHECK:
x= 4, y= -8

3x + y= 4
3(4) + (-8)= 4
12 - 8= 4
4= 4


ANSWER: The x value is 4 and the y value is -8.

Hope this helps! :)

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