Respuesta :

Answer: 21

Step-by-step explanation:

We know 9x - 56 is equal to 6x + 7

So:

9x - 56 = 6x + 7

Add 56 to each side

9x = 6x + 63

Subtract 6x from each side

3x = 63

Now divide each side by 3

x = 21