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noname [10]
3 years ago
11

PLEASE ANSWERRR! FIRST CORRECT ANSWER WILL VOTE BRAINLIEST

Mathematics
1 answer:
FinnZ [79.3K]3 years ago
8 0

Answer:

  • k = 7/4

Step-by-step explanation:

<u>Given system:</u>

  • x + y + 3z = 10,
  • -4x + 3y + 5z = 7,
  • kx + z = 3

<u>Substitute z in the first two equations with z = 3 - kx:</u>

  • x + y + 3(3 - kx) = 10 ⇒ (1 - 3k)x + y = 1 ⇒ y = (3k - 1)x + 1
  • -4x + 3y +5(3 - kx) = 7 ⇒ -(4 + 5k)x + 3y = -8 ⇒ y = 1/3(5k + 4) - 8

In order the two equations above not to have a solution, the lines should be parallel. Parallel lines have equal slopes.

<u>Solve the following equation for k:</u>

  • 3k - 1 = 1/3(5k + 4)
  • 9k - 3 = 5k + 4
  • 4k = 7
  • k = 7/4
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