Respuesta :

Space

Answer:

k = 24

General Formulas and Concepts:

Pre-Algebra

  • Order of Operations: BPEMDAS
  • Equality Properties

Step-by-step explanation:

Step 1: Define

7/8 = 21/k

Step 2: Solve for k

  1. Cross-multiply:                              7k = 168
  2. Divide both sides by 7:                 k = 24

Step 3: Check

Plug in k to verify it's a solution.

  1. Substitute:                    7/8 = 21/24
  2. Simplify:                        7/8 = 7/8

Here we see that 7/8 does indeed equal 7/8. ∴ k = 24 is a solution.

you would use cross multiplication to solve.
7(k) = 8(21) , 7k = 168 , k = 24
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