What is the most difficult in equations? ?

graphing, subsitution, or elimination

explain why : )

Which shows one way to determine the factors of 4x3 + x2 – 8x – 2 by grouping?

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?

Pls math have no ideamultiply and simppify. 2x^2y^3z^2 • 4xy^4x^2