Question

K+m/-7=n solving for k

Answer 1

it depends if it is (K+m)/-7=n or K+(m/-7)=n
if it is (K+m)/-7=n then multiply both sides by -7 (K+m=-7n) and subtract m from both sides (K=-7n-m
if it is K+(m/-7)=n then subtract m/-7 from both sides (K=(m/-7)+n)