15500-12%=

$$\small{\text{
$15500-12\% $
}}
$\\$
\small{\text{
$=15500-(12\%\ of \ 15500) $
}}
$\\$
\small{\text{
$=15500-15500*12\% $
}}
$\\$
\small{\text{
$=15500*1-15500*12\% \quad | \quad 1 = \frac{100}{100}=100*\frac{1}{100}=100\%
$
}}
$\\$
\small{\text{
$=15500*100\%-15500*12\%$
}}
$\\$
\small{\text{
$=15500*(100\%-12\%)$
}}
$\\$
\small{\text{
$=15500*88\% $
}}
$\\$
\small{\text{
$=15500*\frac{88}{100}$
}}
$\\$
\small{\text{
$=155*88 $
}}
$\\$
\small{\text{
$=13640$
}}$$

15500 - 12% =

first find 12% of 15500

15500 x 0.12

now multiply

1860

subtract 1860 from 15500

15500 - 1860

now subtract

13640

and there's your answer!

P.S. for these just remember that you don't know what 12% of 15500 is, so you have to find it and then plug that number in for 12%

You are missing a zero just on the last line Heureka :)