Question

Please help me!

A line that includes the points (d,-1) and (-5,0) has a slope of -1/3. What is the value of d?

Answer 1

d = -2

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

Distributive Property

Equality Properties

• Multiplication Property of Equality
• Division Property of Equality
• Addition Property of Equality
• Subtraction Property of Equality

Algebra I

• Slope Formula:
  `\displaystyle m = (y_2 - y_1)/(x_2 - x_1)`
• Terms/Coefficients

Explanation:

Step 1: Define

Identify

Point (d, -1)

Point (-5, 0)

Slope m = -1/3

Step 2: Solve for d

1. Substitute in variables [Slope Formula]:
   `\displaystyle (-1)/(3) = (0 + 1)/(-5 - d)`
2. Simplify:
   `\displaystyle (-1)/(3) = (1)/(-5 - d)`
3. [Multiplication Property of Equality] Cross-Multiply:
   `\displaystyle -(-5 - d) = 3`
4. (Parenthesis) Distribute negative:
   `\displaystyle 5 + d = 3`
5. [Subtraction Property of Equality] Subtract d on both sides:
   `\displaystyle d = -2`