Can someone explain how complex fractions can be used to solve problems involving ratios?

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

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8

The fraction of defective integrated circuits produced in a photolithography process is being studied. a random sample of 300 circuits is tested, revealing 17 defectives. (a) calculate a 95% two-sided confidence interval on the fraction of defective circuits produced by this particular tool. round the answers to 4 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) calculate a 95% upper confidence bound on the fraction of defective circuits. round the answer to 4 decimal places. p less-than-or-equal-to