If the value of the determinant is 31, find m

Engineering

Mathematics

Introduction to Determinants

Question

If the value of the determinant $∣ \begin{array}{cc} m & 2 \\ - 5 & 7 \end{array} ∣$ is 31, find m

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

Given,

∣ \begin{array}{cc} m & 2 \\ - 5 & 7 \end{array} ∣

⇒ 7 m – ( – 10) = 31

⇒ 7m + 10 = 31

⇒ 7m = 21

⇒ m = 3

Please subscribe our Youtube channel to unlock this solution.