Question

“1.) 7x - 18 = 4x + 21
Explain your work”

Answer 1

x = 13

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

Answer 2

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

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