On my homework 204\306 and 56: 84 is equal to 2\3 but only one can be equal to 2\3

Mary spent a total of $323.14 for a party.she spent a total of $200.22 on food,plus an additional $30.73 for each hour of the party.how long was the party?

Does anyone know of a quizlet or something for edmentrum /plato algebra 1

Aresearch company wants to test the claim that a new multivitamin to improve short term memory. state the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.