Respuesta :

Answer:

  • (4, - 4)

Step-by-step explanation:

Given system:

  • -x + y = 8
  • 7x + 3y = - 16

Multiply the first equation by 7 and add up the equations:

  • -7x + 7y + 7x + 3y = 7*8 - 16
  • 10y = 40
  • y = 4

Find y:

  • -x + 4 = 8
  • -x = 4
  • x = - 4

Solution:

Note that:

  • Given equations: -x + y = 8 and 7x + 3y = -16

Solving the system of equations to find the value of x and y:

  • 7(-x + y = 8)

        7x + 3y = -16

  • -7x + 7y = 56

        7x + 3y = -16

  • 10y = 40
  • => y = 40/10 = 4

Substituting the value of y into any equation to find the value of x:

  • 7x + 3y = -16
  • => 7x + 3(4) = -16
  • => 7x + 12 = -16
  • => 7x = -16 - 12
  • => 7x = -28
  • => x = -28/7 = -4

Putting the values in the form (x,y):

  • (x,y) ⇒ (x = -4,y = 4) ⇒ (-4,4)

Correct option is D.

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