What’s the answer, i’m really confused

Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585

The graph shows the decibel measure for sounds depending on how many times as intense they are as the threshold of sound. noise in a quiet room is 500 times as intense as the threshold of sound. what is the decibel measurement for the quiet room? 20 decibels28 decibels200 decibels280 decibels

Which ordered pair is a solution of the equation? 2x+3y=10