In the x-y plane, the area of the region bounded by the graph of |x+y| + |x-y| = 10 is
Choose one: A) 8 B) 625 C) 16 D) 20 E) 24
I've never seen such kind of question in GMAT before.   OK there can be 4 cases:   |x+y| + |x-y| = 10   A. x+y+x-y = 10 --&gt; x=5   B. x+y-x+y = 10 --&gt; y=5   C. -x-y +x-y= 10 --&gt; y=-5   D. -x-y-x+y=10 --&gt; x=-5   The area bounded by 4 graphs x=5, x=-5, y=5, y=-5 will be square with the side of 4 so the area will be  25*25= 
<gadget id="calculator">  25*25</gadget>
<output>625</output>
625   Answer: 625
<result>B</result>
In the x-y plane, the area of the region bounded by the graph of |x+y| + |x-y| = 10 is