Find the rational number equivalent to 0.490 with 90 repeating?

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).

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =

Solve the triangle. a = 21°, c = 105°, c = 5