What is the additive inverse of -5/7x?

Can someone me and plz do the problem

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 .

If the scale factor between two circles is 2x/5y what is the ratio of their areas?