
= - 20
You can subtract the numbers in the parenthesis:
(3-11) = (-8)
Multiply the denominator to both sides so it cancels out and isolates the variable

× -8 = - 20 × -8
-8 and -8 cancels out
k = 160Quick check:

= -20

= - 20
- 20 = - 20
Yes its right
the answer is:
k =160