हिंदी

Answer the following question: Find the value of k, if the following equations are consistent: (k + 1)x + (k – 1)y + (k – 1) = 0(k – 1)x + (k + 1)y + (k – 1) = 0(k – 1)x + (k – 1)y + (k + 1) = 0 - Mathematics and Statistics

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प्रश्न

Answer the following question:

Find the value of k, if the following equations are consistent:

(k + 1)x + (k – 1)y + (k – 1) = 0
(k – 1)x + (k + 1)y + (k – 1) = 0
(k – 1)x + (k – 1)y + (k + 1) = 0

योग

उत्तर

Given equations are
(k + 1)x + (k – 1)y + (k – 1) = 0

(k – 1)x + (k + 1)y + (k – 1) = 0

(k – 1)x + (k – 1)y + (k + 1) = 0

Since these equations are consistent,

`|("k" + 1, "k" - 1, "k" - 1),("k" - 1, "k" + 1, "k" - 1),("k" - 1, "k" - 1, "k" + 1)|` = 0

Applying C1 → C1 – C2, we get

`|(2, "k" - 1, "k" - 1),(-2, "k" + 1, "k" - 1),(0, "k" - 1, "k" + 1)|` = 0

Applying C2 → C2 – C3, we get

`|(2, 0, "k" - 1),(-2, 2, "k" - 1),(0, -2, "k" + 1)|` = 0

∴ 2(2k + 2 + 2k – 2) – 0 + (k – 1) (4 – 0) = 0

∴ 2(4k) + (k – 1) 4 = 0

∴ 8k + 4k – 4 = 0

∴ 12k – 4 = 0

∴ k = `4/12`

= `1/3`

shaalaa.com
Application of Determinants - Consistency of Three Equations in Two Variables
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 4: Determinants and Matrices - Miscellaneous Exercise 4(A) [पृष्ठ ७७]

APPEARS IN

बालभारती Mathematics and Statistics 1 (Arts and Science) [English] 11 Standard Maharashtra State Board
अध्याय 4 Determinants and Matrices
Miscellaneous Exercise 4(A) | Q II. (10) (i) | पृष्ठ ७७
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