224k views
4 votes
7(2x-5)=21

What is x?

User NielsK
by
4.6k points

1 Answer

5 votes

Answer:

x = 4

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

Explanation:

Step 1: Define Equation

7(2x - 5) = 21

Step 2: Solve for x

  1. Distribute 7: 2x - 5 = 3
  2. Isolate x term: 2x = 8
  3. Isolate x: x = 4

Step 3: Check

Plug in x into the original equation to verify it's a solution.

  1. Substitute in x: 7(2(4) - 5) = 21
  2. Multiply: 7(8 - 5) = 21
  3. Subtract: 7(3) = 21
  4. Multiply: 21 = 21

Here we see that 21 does indeed equal 21.

∴ x = 4 is the solution to the equation.

User Thibaultcha
by
5.1k points