Question

Resolva o sistema linear:

{a + b + c = 1
{6a - b - 4c = 1
{-4a + 6b - c = 0

Answer 1

 • de acordo com o enunciado vem:

   a + b + c = 1    (I)

   6a - b - 4c = 1 (II)

  -4a + 6b - c = 0 (III)

 • (I) + (III)

  -3a + 7b = 1

• 4*(I)

  4a + 4b + 4c = 4

  6a - b - 4c = 1 (II)

  10a + 3b = 5 (*3)

   -3a + 7b = 1 (*10)

  30a + 9b = 15

 -30a + 70b = 10

  79b = 25

 b = 25/79

 10a + 75/79 = 395/79

 10a = 395/79 - 75/79 = 320/79

 a = 32/79

 a + b + c = 1  

 32/79 + 25/79 + c = 79/79

 57/79 + c = 79/79

 c = 79/79 - 57/79

 c = 22/79