Taylor mixed two liquids together in a beaker. the beaker quickly heated up. what does this indicate about the reaction that took place in the beaker?

There are 2 types of reactions with regard to heat energy.
There are exothermic reactions which gives out heat energy during the reaction and there are endothermic reactions which take in heat energy during the reaction.
In this case, when the two liquids were mixed together the beaker heated up, this means that there was an increase in heat energy was given out to the surroundings, therefore this is an exothermic reaction.

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)