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

Answer:

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: $\displaystyle m = \frac{y_2 - y_1}{x_2 - x_1}$
• Terms/Coefficients

Step-by-step 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]:                                                         $\displaystyle \frac{-1}{3} = \frac{0 + 1}{-5 - d}$
2. Simplify:                                                                                                             $\displaystyle \frac{-1}{3} = \frac{1}{-5 - d}$
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:                        $\displaystyle d = -2$