M-9=21

M=30
Is what I got

Right!

Thanks

To verify your answer, let's first substitute the value of M into the equation M - 9 = 21:

30 - 9 = 21

Now, let's solve the equation:

30 - 9 = 21
21 = 21

Since the equation is true, it means that your solution of M = 30 is correct. Well done!