Search any question & find its solution
Question:
Answered & Verified by Expert
The value of $k$ for which the lines $7 x-8 y+5=0,3 x-4 y+5=0$ and $4 x+5 y+k=0$ are concurrent is given by
Options:
Solution:
2744 Upvotes
Verified Answer
The correct answer is:
-45
The lines are concurrent, if $\left|\begin{array}{ccc}7 & -8 & 5 \\ 3 & -4 & 5 \\ 4 & 5 & k\end{array}\right|=0$
$\Rightarrow 7(-4 k-25)+8(3 k-20)+5(15+16)=0 \Rightarrow k=-45$
$\Rightarrow 7(-4 k-25)+8(3 k-20)+5(15+16)=0 \Rightarrow k=-45$
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.