In order to solve the following system of equations by subtraction, which of
the following could you do before subtracting the equations so that one
variable will be eliminated when you subtract them?
4x – 2y=7
3x – 3y=15

A. Multiply the top equation by-3 and the bottom equation by 2.

B. Multiply the top equation by 1/3.
C. Multiply the top equation by 3 and the bottom equation by 4.

D. Multiply the top equation by 15 and the bottom equation by 7.

Farmer dave harvested his corn. he stored 5/9 of his corn in one large silo and 3/4 of the remaining corn in a small silo. the rest was taken to a market to be sold. a. what fraction of the corn was stored in the small silo? 10 points

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

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?