Respuesta :

Answer:

k = -9x^2\y^2 - 12x\y -1

Answer:

k=3 is your answer

Step-by-step explanation:

given equation :

9x²+12xy+(k+1)y²=0

comparing above equation with

ax²+2hxy+by²

we get

a=9

h=12/2=6

b=k+1

since lines are coincident

ø=0

Tan0=±[2√(h²-ab)]/(a+b)

we get

h²=ab

6²=9(k+1)

36/9=k+1

4=k+1

k=4-1=3