Question

for which value of k will the following system of linear equations have unique solution x+2y=5;3x+ky+15=0

Answer 1

x+2y=5
Taking x=1 & y=2
Subtitute the values
1+2×2=5



Giving these values in 2nd equation
3×1+k×2+15=0
3+2k+15=0
2k+18=0
2k= -18
K =-9