I don't know if I have the right answer?

[rachael724]

Determine the value of the constant k so that the system
8x - 16y = 10
-4x + 8y = k
will be dependent.

a. -10
b. -8
c. -12
d. -5 Is this right?
e. none of these

 

[stapel]

We'll be glad to check if your answer (mentioned in your subject line) is correct, but you'll need to tell us which answer you chose.

Thank you.

Eliz.

 

[rachael724]

umm, do we need glasses? d asks if it is the right one

 

[stapel]

umm, do we need glasses?

Already got bifocals, actually. Perhaps they need a good cleaning...? :wink:

Sorry 'bout that. Anyway....

To check the answer to any "solving" problem, plug your solution back into the original exercise. In this case:

. . . . .Let k = -5. Then:

. . . . .8x - 16y = 10
. . . . .-4x + 8y = -5

. . . . .Multiplying the second equation by -2,
. . . . .we then get:

. . . . .8x - 16y = 10
. . . . .8x - 16y = 10

. . . . .Since the lines are the same, the system
. . . . .is dependent.

So, yes, you have the correct answer.

I'm gonna go clean my specs now....

Eliz.