Factor x^6+6x^5-5x^4-6x^3-38x^2-252x+168

How do you write y-10=2 (x-8) in standard form

Asource of laser light sends rays ab and ac toward two opposite walls of a hall. the light rays strike the walls at points b and c, as shown below: what is the distance between the walls?

X^2/100+y^2/25=1 the length of the major axis is: a)5 b)10 c)20