Question

5. For what value of k the following pair of linear
equations has unique solution?
7x + 2y =k
9x – 4y = 12​

Answer 1

if the equations has unique solution then

a1/a2 is not equals to b1/b2=C1/C2

7/9is not equals to 2/-4=-k/-12

7/9is not equals to 1/-2=k/12

7/9=k/12

84=9k

k =84/9

k=28/3