Respuesta :

Space

Answer:

x = 13

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

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

Algebra I

  • Terms/Coefficients

Step-by-step explanation:

Step 1: Define

Identify

7x - 18 = 4x + 21

Step 2: Solve for x

  1. [Subtraction Property of Equality] Subtract 4x on both sides:                      3x - 18 = 21
  2. [Addition Property of Equality] Add 18 on both sides:                                    3x = 39
  3. [Division Property of Equality] Divide 3 on both sides:                                   x = 13

Answer:

x = 13

Step-by-step explanation:

7 x - 18 = 4 x + 21

Subtract 4x on both side

7x - 4 x - 18 = 4x - 4x + 21

3 x - 18 = 21

Add 18 on each side

3 x - 18 + 18 = 21 + 18

3 x = 39

Divided each side by 3

3 x / 3 = 39 / 3

x = 13