Four and one half times five and one half

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

If 3x+8=3x+8 is it one solution or no solution

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin.how many doctors use brand x aspirin