I don’t understand this at all

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

One astronomical unit (1 au) is about 1.496 alt tag missing. kilometers. if you wrote this number of kilometers in regular decimal notation (for example, 528 and 3,459 are written in regular decimal notation), how many zeros would your number have?

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.