Question

When 9 is subtracted from a number then divided by 2, the answer is 4. What is the number?

Answer 1

$x-\ number\\\\ \frac{x-9}{2}=4\ \ \ |Multiply\ by\ 2\\\\ x-9=8\ \ \ |Add\ 9\\\\ x=17\\\\Number\ is\ 17.$

Answer 2

$(x-9):2=4 \\\\ x-9=4*2 \\\\ x-9=8 \\\\ x=8+9 \\\\ \boxed{x=17}$