With last equation i don't understand at !

Asystematic approach to problem solving is called a (an)

What occurs during a combustion reaction

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water