Question

If I add 9 to my secret number, I'll get a number that is 90% more than the number I'll get if I subtract 9 from my secret number.
What is my secret number?

Answer 1

thanjks for helping me

Answer 2

it's a secret ;)

Answer 3

help me

Answer 4

i think it is 21

Answer 5

Let the number be x.
\[x+9=x-9+\frac{ 90 }{ 100 } x \]
find x.

Answer 6

you have to be patient, or try the problem yourself working backwards

Answer 7

is it 21

Answer 8

the way I read it is:

If I add 9 to my secret number, I'll get a number that is 90% more than the number I'll get if I subtract 9 from my secret number.

\(\huge x+9=0.9(x-9)\)