If the system of equations \(\begin{aligned}& x+2 y-3 z=2 \\& 2 x+\lambda y+5 z=5 \\& 14 x+3 y+\mu z=33\end{aligned}\) h…
Q1 FREE PREVIEW
PYQIf the system of equations
\(\begin{aligned}& x+2 y-3 z=2 \\& 2 x+\lambda y+5 z=5 \\& 14 x+3 y+\mu z=33\end{aligned}\)
has infinitely many solutions, then \(\lambda+\mu\) is equal to :
[JEE Main 2025, 24 Jan (Shift 2)]
✓ Correct answer: c)
12
Explanation
Given
\(x+2y-3z=2\)
\(2x+\lambda y+5z=5\)
\(14x+3y+\mu z=33\)
For infinitely many solutions, the third equation must be a linear combination of the first two:
Checking the standard condition for infinitely many solutions using determinants,
\(\Delta=\begin{vmatrix}1\&2\&-32\&\lambda\&514\&3\&\mu\end{vmatrix}=0\)
\(\Delta_x=\Delta_y=\Delta_z=0\)
\(\lambda=4,\qquad \mu=8\)
\(\lambda+\mu=12\)
Practice more JEE Maths PYQs
See every question on Matrices, or browse the full JEE question bank.
See all questions on Matrices →