The angle between two lines, $$2y+x=3$$ and $$5y+x=3$$, is most closely:
A. $$20^(circ)$$
B. $$18^(circ)$$
C. $$15^(circ)$$
D. $$14^(circ)$$
Three lines are defined by the three equations:
$$x+y=0$$
$$2x-y=0$$
$$x+2y=2$$
The three lines form a triangle with vertices at:
The equation of a sphere with center at (-3, 2, 5) and a radius of 6 is: