Get Answers to all your Questions

header-bg qa

Need solution for RD Sharma maths class 12 chapter Algebra of matrices exercise 4.3 question 24 sub question (i) maths

Answers (1)

Answer: x = -2

Hint: Matrix multiplication is only possible, when the number of columns of first matrix is equal to the number of rows of second matrix.

Given: \left[\begin{array}{lll} 1 & 1 & x \end{array}\right]\left[\begin{array}{lll} 1 & 0 & 2 \\ 0 & 2 & 1 \\ 2 & 1 & 0 \end{array}\right]\left[\begin{array}{l} 1 \\ 1 \\ 1 \end{array}\right]=0\\

Firstly, we multiply first two matrices,

\Rightarrow\left[\begin{array}{lll} 1+0+2 x & 0+2+x & 2+1+0 \end{array}\right]\left[\begin{array}{l} 1 \\ 1 \\ 1 \end{array}\right]=0\\\\ \Rightarrow\left[\begin{array}{lll} 2 x+1 & 2+x & 3 \end{array}\right]\left[\begin{array}{l} 1 \\ 1 \\ 1 \end{array}\right]=0\\\\\\\ \Rightarrow[2 x+1+2+x+3]=0 \\\\\ \Rightarrow 3 x+6=0\\\\ \Rightarrow 3 x=-6\\\\ \Rightarrow x=-\frac{6}{3}=-2\\\\ \Rightarrow x=-2

Posted by

infoexpert22

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads