Please help I don't understand exponents

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

For the equations below which statement is true ? -2x=14 6x=-42

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?