Please help me! Thanks!

[maggie0160]

Can someone show me how to do this?

Determine the value of the constant k so that the system
8x - 16y = 20
-4x + 8y = k
will be dependent.

a. -10
b. -8
c. -12
d. -5
e. none of these

Would the answer be a -10 just from looking at it that is what it looks like to me.

 

[tkhunny]

I think you have it. Everything in #1 would then be "-2" times the corresponding piece in #2.