Question

the difference of 9 and a number is 11 what is the number

Answer 1

Let the no be x

x-9=11
x=11+9
x=20

so the no is 20

Answer 2

Let the number be x.
According to the question,
x-9=11
or, x= 11+9
So, x= 20

This can also be possible,
9-x = 11
or, 9-11 = x
So, x = -2