Need with #s 2,4,5,6,7, and 10 don't understand how to do these complex triangles where theyre combined don't have to answer all if someone could explain step by step for number 2 i'm sure i can figure the rest out

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?