Find the greatest common factor of 15 and 45.

In a certain pentagon, the interior angles are a,b,c,d,e where a,b,c,d,e are integers strictly less than 180. ("strictly less than 180" means they are "less than and not equal to" 180.) if the median of the interior angles is 61 and there is only one mode, then what are the degree measures of all five angles?

What is the slope of a line that is perpendicular to y = 3x + 1

Which expression is equivalent to 2x^2+7x+4?