# Ex 4.6, 7 - Chapter 4 Class 12 Determinants (Term 1)

Last updated at Jan. 23, 2020 by Teachoo

Last updated at Jan. 23, 2020 by Teachoo

Transcript

Ex 4.6, 7 Solve system of linear equations, using matrix method. 5x+ 2y = 4 7x + 3y = 5 The system of equations is 5x + 2y = 4 7x + 3y = 5 Writing equation as AX = B [โ 8(5&2@7&3)] [โ 8(๐ฅ@๐ฆ)] = [โ 8(4@5)] Hence A = [โ 8(5&2@7&3)], X = [โ 8(๐ฅ@๐ฆ)] & B = [โ 8(4@5)] Calculating |A| |A| = |โ 8(5&2@7&3)| = 5(3) โ 7(2) = 15 โ 14 = 1 โ 0 Since |A|โ 0, System of equations is consistent & has a unique solution Now, AX = B Solution is X = A-1 B Calculating Aโ1 A-1 = 1/(|A|) adj (A) A = [โ 8(5&2@7&3)] adj A = [โ 8(5&2@7&3)] = [โ 8(3&โ2@โ7&5)] Now, A-1 = 1/(|A|) adj A Putting values = 1/1 [โ 8(3&โ2@โ7&5)] = [โ 8(3&โ2@โ7&5)] Now X = A-1 B [โ 8(๐ฅ@๐ฆ)] = [โ 8(3&โ2@โ7&5)] [โ 8(4@5)] [โ 8(๐ฅ@๐ฆ)] = [โ 8(3(4)+(โคถ7โ2)5@โ7(4)+5(5))] [โ 8(๐ฅ@๐ฆ)] = [โ 8(2@โ3)] Hence, x = 2 & y = โ3

Ex 4.6

Ex 4.6, 1
Deleted for CBSE Board 2022 Exams

Ex 4.6, 2 Deleted for CBSE Board 2022 Exams

Ex 4.6, 3 Important Deleted for CBSE Board 2022 Exams

Ex 4.6, 4 Deleted for CBSE Board 2022 Exams

Ex 4.6, 5 Important Deleted for CBSE Board 2022 Exams

Ex 4.6, 6 Deleted for CBSE Board 2022 Exams

Ex 4.6, 7 You are here

Ex 4.6, 8

Ex 4.6, 9

Ex 4.6, 10 Important

Ex 4.6, 11

Ex 4.6, 12

Ex 4.6, 13 Important

Ex 4.6, 14 Important

Ex 4.6, 15 Important

Ex 4.6, 16 Important

Chapter 4 Class 12 Determinants (Term 1)

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.