Differentiate the given solution:

Substitute
and
into the ODE:

and it's easy to see the left side indeed reduces to 0.
Answer:
-50
Step-by-step explanation:
it could be X-50=?
0.7 is rounded to the tenth place
3/9 is already a fraction, you do not need to change it. 3/9 is not more than 9/9