Please hurry! Which best explains whether a triangle with side lengths 5 cm, 13 cm, and 12 cm is a right triangle?

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).

1mile equals approximately 1.6 kilometers. which best approximates the number of miles in 6 kilometers?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15