11/12 - 3/4? i don't really get math but i try my best

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 .

The measure of angle 0 is 600 degrees

How do i i solve this equation? -18 = x/3 + 3