Please help me on this

The probability of winning something on a single play at a slot machine is 0.11. after 4 plays on the slot machine, what is the probability of winning at least once

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).

What is the solution of the systems of equations? y=2/3x+3 x=-2