JEE Main 2018
Matrices & Determinants
Matrices and Determinants
Easy
Question
The number of values of k for which the system of linear equations, (k + 2)x + 10y = k kx + (k +3)y = k -1 has no solution, is :
Options
Solution
System of linear equation have no solution, determinant of coefficient = 0 \left| {\matrix{ {k + 2} & {10} \cr k & {k + 3} \cr } } \right| = 0 (k + 2) (k + 3) 10 K = 0 k 2 5k + 6 = 0 k = 2, 3 When, k = 2 then equations become, 4x + 10y = 2 and 2x + 5y = 1 It has in finite number of solutions. When k = 3, equations becomes 5x + 10y = 3 3x + 6y = 2 Those equation has no solutions. When k = 3, then system of equations have no solutions.