Search any question & find its solution
Question:
Answered & Verified by Expert
$\left|\begin{array}{lll}24 & 25 & 26 \\ 25 & 26 & 27 \\ 26 & 27 & 27\end{array}\right|$ is equal to
Options:
Solution:
2545 Upvotes
Verified Answer
The correct answer is:
1
Let $\Delta=\left|\begin{array}{lll}24 & 25 & 26 \\ 25 & 26 & 27 \\ 26 & 27 & 27\end{array}\right|$
Applying $R_2 \rightarrow R_2-R_1$
and $\quad R_3 \rightarrow R_3-R_2$
$\begin{aligned}
\Delta & =\left|\begin{array}{ccc}
24 & 25 & 26 \\
1 & 1 & 1 \\
1 & 1 & 0
\end{array}\right| \\
& =1[25-26]-1[24-26] \\
& =-1+2=1
\end{aligned}$
Applying $R_2 \rightarrow R_2-R_1$
and $\quad R_3 \rightarrow R_3-R_2$
$\begin{aligned}
\Delta & =\left|\begin{array}{ccc}
24 & 25 & 26 \\
1 & 1 & 1 \\
1 & 1 & 0
\end{array}\right| \\
& =1[25-26]-1[24-26] \\
& =-1+2=1
\end{aligned}$
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.