6d-24=11d-18d-54
6d-24=-7d-54
Move -7d to the other side
Sign changes from -7d to -7d
6d+7d-24=-7d+7d-54
13d-24=-54
Move -24 to the other side
Sign changes from -24 to +24
13d-24+24=-54+24
13d=-54+24
13d=-30
divide both sides by 13 to get d by itself
13d/13=-30/13
Answer:
d=-30/13