A=4-b
2a+b=1

SIMULTANEOUS EQUATIONS
help pls

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

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?

Line segment eg is partitioned by point f in the ratio 1: 1. point e is at e (0, 4), and point f is at (1, 3). what are the coordinates of point g? (−1, 5) (2, 2) (3, 1) (4, 0)