Find x if

Engineering

Mathematics

Multiplication of Matrices

Symmetric and Skew Symmetric Matrices

Question

Find x if $[1 x 1] [\begin{array}{ccc} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 3 & 2 & 5 \end{array}] [\begin{array}{c} 1 \\ - 2 \\ 3 \end{array}] = 0$

College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

[1 x 1] [\begin{array}{ccc} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 3 & 2 & 5 \end{array}] [\begin{array}{c} 1 \\ - 2 \\ 3 \end{array}] = 0

= [1 \times 1 + x \times 4 + 1 \times 3 1 \times 2 + x \times 5 + 1 \times 2 1 \times 1 + x \times 6 + 1 \times 5] [\begin{array}{c} 1 \\ - 2 \\ 3 \end{array}] = 0

= [4 + 4 x 4 + 5 x 6 + 6 x] [\begin{array}{c} 1 \\ - 2 \\ 3 \end{array}] = 0

= [4 + 4x – 8 – 10x + 18 + 18x] = 0

4 + 4x – 8 – 10x + 18 + 18x = 0

⇒ 12x = – 14

∴ x = \frac{- 14}{12} = \frac{- 7}{6}

Please subscribe our Youtube channel to unlock this solution.