Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202310 AprilMorning Shift
Exam
JEE Main
Year
2023
Date
10 April
Shift
Morning Shift
Subject
Mathematics
Chapter
Determinants

JEE Main 2023 · 10 April · Morning Shift · Mathematics · Determinants

For the system of linear equations 2x - y + 3z = 5 3x + 2y - z = 7...

For the system of linear equations

2x−y+3z=52x - y + 3z = 5

3x+2y−z=73x + 2y - z = 7

4x+5y+\alphaz=β4x + 5y + \alphaz = \beta,

which of the following is NOT correct?

Options

  1. AThe system has infinitely many solutions for α=–5\alpha = – 5 and β=9\beta = 9
  2. BThe system has infinitely many solutions for α=−6\alpha = - 6 and β=9\beta = 9
  3. CThe system in inconsistent for α=–5\alpha = – 5 and β=8\beta = 8
  4. DThe system has a unique solution for α≠–5\alpha \ne – 5 and β=8\beta = 8

Correct answer

B. The system has infinitely many solutions for α=−6\alpha = - 6 and β=9\beta = 9

Step-by-step solution

Given,

For the system of linear equations

2x−y+3z=52x - y + 3z = 5

3x+2y−z=73x + 2y - z = 7

4x+5y+\alphaz=β4x + 5y + \alphaz = \beta,

Now finding,

D = \left|\begin{cases}2 & - 1 & 3 \\ 3 & 2 & - 1 \\ 4 & 5 & \alpha\end{cases}\right|

⇒D=2(2α+5)+(3α+4)+3(7)⇒ D = 2\left(2\alpha + 5\right) + \left(3\alpha + 4\right) + 3\left(7\right)

⇒D=7α+35⇒ D = 7\alpha + 35

Now we know that, for unique solutionD≠0⇒α≠–5D \ne 0 ⇒ \alpha \ne – 5

So, in option \left(B\right)\alpha = – 6 corresponds to infinitely many solution, which is completely wrong hence, this is answer.

Practice Determinants on Quantrex Academy →

More from Determinants

If the system of linear equations: x+y+z=6 , x+2y+5z=10 , 2x+3y+λ z=μ has infinitely many… JEE Main 2026The sum of all possible values of θ ∈ [0, 2π] , for which the system of equations : x 3θ… JEE Main 2026If f: N arrow Z is defined by f(n) = vmatrix n & -1 & -5 -2n^2 & 3(2k+1) & 2k+1 -3n^3 &… JEE Main 2026Consider the system of linear equations in x, y, z : x + 2y + tz = 0 , 6x + y + 5tz = 0… JEE Main 2026If the system of equations: x+y+z=5 x+2y+3z=9 x+3y+λ z=μ has infinitely many solutions… JEE Main 2026If the system of equations x + 5y + 6z = 4 , 2x + 3y + 4z = 7 , x + 6y + az = b has… JEE Main 2026Let α, β ∈ ℝ be such that the system of linear equations x + 2y + z = 5 2x + y + α z = 5… JEE Main 2026The system of linear equations x+y+z=6 2 x+5 y+a z=36 x+2 y+3 z=b has JEE Main 2026Among the statements : I: If | array ccc 1 & α & β α & 1 & γ β & γ & 1 array |=| array… JEE Main 2026Let n be the number obtained on rolling a fair die. If the probability that the system… JEE Main 2026If the system of equations 3 x+y+4 z=3 2 x+α y-z=-3 x+2 y+z=4 has no solution, then the… JEE Main 2026Let the system of equations aligned & x+5 y-z=1 & 4 x+3 y-3 z=7 & 24 x+y+λ z=μ aligned λ… JEE Main 2025Let the system of equations : aligned & 2 x+3 y+5 z=9 & 7 x+3 y-2 z=8 & 12 x+3 y-(4+λ)… JEE Main 2025If y(x)=| array ccc x & x & x+ x+1 27 & 28 & 27 1 & 1 & 1 array |, x ∈ ℝ , then (d^2… JEE Main 2025If the system of equation aligned & 2 x+λ y+3 z=5 & 3 x+2 y-z=7 & 4 x+5 y+μ z=9 aligned… JEE Main 2025If the system of linear equations aligned & 3 x+y+β z=3 & 2 x+α y-z=-3 & x+2 y+z=4… JEE Main 2025 Full Determinants list Determinants JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs