Hi! I agree with an answer already submitted; however, I used a different formula to calculate it.
“Y varying directly as x” means that y and x always have the same ratio.
k is known as the constant of variation
k = y / x
k = -12 / 6
k = -2
When k<0 (k is negative),
If x increases then the value of y decreases, or if x decreases then the value of y increases.
-2 = y / x
-2 = 26 / x
x = -2 / 26
x = -13