Subtract 65 from d2 to get 6d−5d+12.
To subtract raitonal expressions, both fractions must have the same denominator.
We can create a common denominator by multiplying the first fraction by 6 and the second by d.
d2−65=d⋅62⋅6−6⋅d5⋅d==6d12−6d5d=6d−5d+12