For the set b= { 3, 5, 7, ,9 , 12, 17, } determine n(b) n(b) =

For the set B= { 3, 5, 7, ,9 , 12, 17, } determine n(B)

n is asking for the count of numbers in the set.

Set B has 6 numbers.

n(B) = 6

9514 1404 393

Step-by-step explanation:

The marked angles are all "interior" -- between the parallel lines. Ones on the same side of the transversal (t) are called "same-side" or "consecutive" interior angles. Angles 1 and 4, 2 and 3 are pairs of consecutive interior angles.

Angles on opposite sides of the transversal are called "alternate" interior angles. Pairs 1 and 3, and 2 and 4 are pairs of alternate interior angles.

Alternate interior angles are congruent. Consecutive interior angles are supplementary (as are the angles of any linear pair).

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1) Angles ∠1 and ∠3 are congruent.

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2) Using the above fact, we can set the expressions for the angle measures equal to solve for x.

  5x -2 = 2x +55

  5x = 2x +57 . . . . . add 2

  3x = 57 . . . . . . . . . subtract 2x

  x = 19 . . . . . . . . . . divide by 3

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3) Angle 1 is ...

  ∠1 = 5x -2 = 5(19) -2 = 93

Angle 4 is its supplement.

  ∠4 = 180 -∠1 = 180 -93

  ∠4 = 87 . . . degrees