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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).

Lisa has three classes that each last 50 minutes. what is the total number of minutes of the three classes

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180