If x and y are numbers such that (x+8)(y-8)=0, what is the smallest possible value of x^2 + y^2
Pick: A) 4 B) 24 C) 54 D) 64 E) 94
From (x+8)(y-8)=0 it follows that either, x=-8 or y=8. Thus either x^2=64 or y^2=64.   Now, if x^2=64, then the least value of y^2 is 0, so the least value of x^2 + y^2 = 64 + 0= 
<gadget id="calculator">64 + 0</gadget>
<output>64</output>
64.   Similarly if y^2=64, then the least value of x^2 is 0, so the least value of x^2 + y^2 = 0 + 64= 
<gadget id="calculator">0 + 64</gadget>
<output>64</output>
64.   Answer: 64.
<result>D</result>
If x and y are numbers such that (x+8)(y-8)=0, what is the smallest possible value of x^2 + y^2