In the coordinate plane, points (x, 2) and (10, y) are on line k. If line k passes through the origin and has slope 1/2, then x + y =  Pick:
A) 4.5  B) 7  C) 9  D) 11  E) 12
Line k passes through the origin and has slope 1/2 means that its equation is y=1/2*x.   Thus: (x, 2)=(4, 2) and (10, y) = (10,5) --&gt; 4+5=2+5=9.   Answer: 9.
<result>C</result>
In the coordinate plane, points (x, 2) and (10, y) are on line k. If line k passes through the origin and has slope 1/2, then x + y =