Where is the mistake?

2x + 3y = 13

y = 2x + 1

1. 2x + 3(2x+1) = 13

2. 2x + 6x + 3 = 13

3. 4x = 16

4. x = 4

5. y = 2(4) + 1

6. y = 9

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable

Which of the following is an equation of a line parallel to the equation y=4x+1?