Help! Pls in need of some Help.

Volume of cylinder with a radius of 8cm and height of 25 cm

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

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 .