-6(3-k) = 6(1+3k)
-6 x -k is going to give you a positive number while -6 x 3 is going to be a -18.
1) Simplify your equation:
-18 + 6k = 6 + 18k
2) Use SAMDEB (it is an acronym you use to find the order of operation - what you do first when you solve an equation...) subtraction, addition, multiplication, division, exponents, brackets. In this case, we have subtraction and addition - it doesn't matter which one you do first...
-18 + 6k = 6 + 18k
-18 = 6 + 18k - 6k
-18 = 6 + 12k
-18 - 6 = 12k
-24/12 = 12k/12
-2 = k