# Example 16 - Chapter 4 Class 12 Determinants

Last updated at April 16, 2024 by Teachoo

Examples

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Example 5 Important

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Example 7 Important

Example 8

Example 9

Example 10

Example 11 Important

Example 12

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Example 14

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Example 16 You are here

Example 17 Important

Example 18

Example 19 Important

Question 1 Deleted for CBSE Board 2025 Exams

Question 2 Deleted for CBSE Board 2025 Exams

Question 3 Deleted for CBSE Board 2025 Exams

Question 4 Important Deleted for CBSE Board 2025 Exams

Question 5 Important Deleted for CBSE Board 2025 Exams

Question 6 Deleted for CBSE Board 2025 Exams

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Question 11 Important Deleted for CBSE Board 2025 Exams

Question 12 Deleted for CBSE Board 2025 Exams

Question 13 Important Deleted for CBSE Board 2025 Exams

Question 14 Important Deleted for CBSE Board 2025 Exams

Question 15 Important Deleted for CBSE Board 2025 Exams

Chapter 4 Class 12 Determinants

Serial order wise

Last updated at April 16, 2024 by Teachoo

Example 16 Solve the system of equations 2x + 5y = 1 3x + 2y = 7 Step 1 Write equation as AX = B [โ 8(2&5@3&2)] [โ 8(๐ฅ@๐ฆ)] = [โ 8(1@7)] A = [โ 8(2&5@3&2)] , X = [โ 8(๐ฅ@๐ฆ)] , B = [โ 8(1@7)] Step 2 Calculate |A|, A = [โ 8(2&5@3&2)] |A| = |โ 8(2&5@3&2)| = 2 ร 2 โ 5 ร 3 = 4 โ 15 = โ 11 Since |๐จ| โ 0, System is consistent and the system of equations has a unique solution AX = B X = A-1 B Step 3 Calculating X = A-1 B Here, A-1 = 1/(|A|) adj (A) adj A = [โ 8(2&5@3&2)] = [โ 8(2&โ5@โ3&2)] Now, A-1 = 1/(|A|) adj A Putting values = ๐/(โ๐๐) [โ 8(๐&โ๐@โ๐&๐)] & B = [โ 8(1@7)] Now X = A-1 B [โ 8(๐ฅ@๐ฆ)] = (โ1)/11 [โ 8(2&โ5@โ3&2)] [โ 8(1@7)] [โ 8(๐ฅ@๐ฆ)] = (โ1)/11 [โ 8(2(1)+(โคถ7โ5)7@โ3(1)+2(7))] [โ 8(๐ฅ@๐ฆ)] = (โ1)/11 [โ 8(2โ35@โ3+14)] = (โ1)/11 [โ 8(โ33@11)] = [โ 8(โ33 ร (โ1)/11@11 ร (โ1)/11)] [โ 8(๐ฅ@๐ฆ)] = [โ 8(3@โ1)] Hence x = 3 & y = โ 1