Find all numbers for which the rational expression is undefined. If the rational expression is defined for all real numbers so state 7x
(9x – 13)(x + 2)

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .