Please help me i don't understand

Solve 2x2 + 8 = 0 by graphing the related function. there are two solutions: . there are no real number solutions. there are two solutions: 2 and -2

Simplify the rational expression. state any restrictions on the variable. t^2-4t-12 / t-8 the / is a fraction sign.

Abc manufacturing has a policy that it will reject a shipment of parts from its supplier if inspectors find any defective parts in a random sample of 6 parts from the shipment. the supplier has been in business many years and has a long-term defective rate for parts of 6.2% what is the probability that a shipment will be rejected after a given sample of parts is checked?