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6. What is the value of x in the solution to the systems of linear equations shown below?
2x - 2y+z=3
5y-z= -31
x+ 3y + 2z = -21

Respuesta :

Annyohasayo

Step-by-step explanation:

[tex]1) \: \: 2x - 2y + z = 3 \\ 2x = 3 + 2y - z \\ x = \frac{3 + 2y - z}{2} \\ \\ 2) \: \: \: not \: any \: \: \: x \: \: \: available \: \: \\ \\ 3) \: \: x + 3y + 2z = - 21 \\ x = - 21 - 3y - 2z[/tex]

s1m1

Answer:

x= -5

Step-by-step explanation:

5y-z= -31, add z and 31 to both sides

5y+31 = z, substitute z in the other two given equations

2x - 2y+z=3

2x-2y +5y+31 = 3, combine like terms and subtract 31 from both sides

2x+3y = -28

x+ 3y + 2z = -21

x+3y +2(5y+31) = -21, distribute 2 over the addition parenthesis

x+3y +10y+62 = -21, combine like terms and subtract 62 from both sides

x+13y = -83

Now we have 2 equations  with 2 variables x and y to solve

2x+3y = -28

x+13y = -83

Because we need to find x then from the first equation we can write that

3y = -2x-28, subtract 2x from both sides and the divide both sides by 3

y = (-2x-28)/3, substitute this in the second equation

x + [13(-2x-28)/3] = -83 , distribute 13 . over the subtraction parenthesis

(3x/3)+[(-26x - 364) /3= -83, find the common denominator

3x+[(-26x - 364) = -83*3 , cross multiply

3x -26x = -249 +364, add 364 to both sides

- 23x = 115, divide both sides by (-23)

x= -5