To subtract numbers involving fractions, both have to have the same DENOMINATOR.
15/2152 has the denominator 2.
-45−45 has the denominator 1.
Since 2 and 1 are not the same, change -45−45 to have a denominator of 2 to make both fractions have the same denominator.
To give -45−45 a denominator of 2, multiply -45−45 by 2/222.
[We can multiply by 2/222 because 2/2 = 122=1, which means we didn't change the original problem! ]
You should end up with 15/2 - 90/2152−902 .
[The 90 came from -45 * 2 = -90−45⋅2=−90]
Now that they have the same denominator, subtract 90 from 15 to get your new numerator, -75−75!
15-90=-7515−90=−75
Keep the DENOMINATOR as 22 because when subtracting fractions, the denominator DOES NOT CHANGE.
-75/2−752 cannot be simplified, so your final answer should be -75/2−752 .