1. 20% tip on a 30$ haircut 2. $80 gift marked up 60%
3. 7% tax on a $3 soda with an $8 burger

please help me :/

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).

Diana is painting statues she has 7/8 of a liter of paint each statue requires 1/20 of a liter of paint how many statues can she paint?

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)