Prove that (x+y)(x-y)+(y+z)(y-z)+(z+x)(z-x)=0

Martha needs 22.25 strawberries for every 5 smoothies she makes. complete the table to see how many strawberries she would need to make 10 smoothies and 20 smoothies.

If square root x = -7, then x= -49 true or false

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?