What is a matrix? what is it used for?

1- identificar select the category that corresponds to each term. january 23 11: 59 pm unlimited attempts remaining grade settings 276-279 vocabulary list modelo fiesta quinceañera casada adolescencia viudo juventud navidad niñez vejez aniversario de bodas divorciado madurez cumpleaños soltera

Suppose that in 2008 , 840,800 citizens died of a certain disease assuming the population of teh country is 399 miliion, what is the mortality rate in units of deaths per 100,000 people?

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.