Respuesta :

GloomKC

Answer:

7

Step-by-step explanation:

6*7=42

9*7=63

63-42

Answer:

number is 7

Step-by-step explanation:

let the number be n , then

6n = 9n - 21 ( add 21 to both sides )

21 + 6n = 9n ( subtract 6n from both sides )

21 = 3n ( divide both sides by 3 )

7 = n

That is the number is 7