Find the number of real number solutions for the equation. x^2-3x+8=0

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).

Simplify the expression 10/11(22z) + (a+5) -1

The trigonometric ratios sine and secant are reciprocals of each other