Thanks to anyone who helps!

Step-by-step explanation:

Look at the determinant.

a = k

b = 1

c = k

sqrt(b^2 - 4*k*k)

sqrt(1 - 4k^2)

The only way this can work out to repeated solutions is if k = +/- 1/2

That way 1 - 4(1/2)^2 = 0   or 1 - 4*(-1/2)^2 = 0

That way both solutions will be

-b / 2a

-1 / 2/(1/2) = - 1

or

-1 / 2(-1/2) = 1

So the answer is k = 1/2, - 1/2

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870