What is the first and secon step to solving x^2-16/25=0 ?

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

I’m still confused on how to work the percentages

Which expression is a factor of 12x2 + 29x – 8? x – 8 2x – 1 3x + 8 4x + 1