Help me plz owo ASAP

What statement is true? 2x^2-9x+2=-1

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 .

What is the value of x when x + 7 = 21?