65.9k views
0 votes
Help please for 40 points!! This is due tonight and i don’t know how to do it

Help please for 40 points!! This is due tonight and i don’t know how to do it-example-1

1 Answer

2 votes

Answer:

x = -8

m∠BDC = 68°

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

Equality Properties

Geometry

  • Definition of a Line: A line is 180°

Step-by-step explanation:

Step 1: Set up Equation

m∠BDC + m∠CDA = 180°

(-7x + 12)° + (-8x + 48)° = 180°

Step 2: Solve for x

  1. Combine like terms: -15x + 60 = 180
  2. Isolate x term: -15x = 120
  3. Isolate x: x = -8

Step 3: Find m∠BDC

  1. Define: m∠BDC = (-7x + 12)°
  2. Substitute in x: m∠BDC = (-7(-8) + 12)°
  3. Multiply: m∠BDC = (56 + 12)°
  4. Add: m∠BDC = 68°
User Yerke
by
4.8k points