The work of a student to solve a set of equations is shown below: Equation 1: m = 8 + 2n
Equation 2: 4m = 4 + 4n

Step 1: −4(m) = −4(8 + 2n)
4m = 4 + 4n
Step 2: −4m = −32 − 8n
4m = 4 + 4n
Step 3: −4m + 4m = −32 − 8n + 4n
Step 4: 0 = −32 − 4n
Step 5: n = − 8
In which step did the student first make an error?

5x + 2 = 12 solve the following equation. then place the correct number in the box provided.

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?

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?