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Line A passes through the points (1, -1) and (-2, 8).
​Line B is perpendicular to line A.
​Select the slope of line B below:

A) −3
B) −13
C) 3
D) 13

Respuesta :

Space

Answer:

D) 1/3

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

  1. Brackets
  2. Parenthesis
  3. Exponents
  4. Multiplication
  5. Division
  6. Addition
  7. Subtraction
  • Left to Right  

Algebra I

  • Coordinates (x, y)
  • Slope Formula: [tex]\displaystyle m = \frac{y_2-y_1}{x_2-x_1}[/tex]
  • Perpendicular lines are the negative reciprocal to the given line

Step-by-step explanation:

Step 1: Define

Identify

Point (1, -1)

Point (-2, 8)

Step 2: Find slope m

Simply plug in the 2 coordinates into the slope formula to find slope m.

Line A

  1. Substitute in points [Slope Formula]:                                                              [tex]\displaystyle m = \frac{8--1}{-2-1}[/tex]
  2. [Fraction] Subtract:                                                                                           [tex]\displaystyle m = \frac{9}{-3}[/tex]
  3. [Fraction] Divide:                                                                                               [tex]\displaystyle m = -3[/tex]

Line B

  1. Negative:                                                                                                           [tex]\displaystyle m = 3[/tex]
  2. Reciprocate:                                                                                                      [tex]\displaystyle m = \frac{1}{3}[/tex]