<p>I know this may sound dumb but if 3<x<7 wouldn't the range of values for x be 4,5,6? Not 3,4,5,6,7 since the values are not equal to?</p>
<p>Your mind is automatically making values of x and y round integers. Does the question specify integers? No, it doesn’t. They will always mention whether or not to use 'em.</p>
<p>Therefore, x actualy ranges from like 3.0000001 to 6.99999999 and y ranges from like 4.00000001 to 6.99999999. From there, it’s easy to find the bounds, -4 to 3 for x-y.</p>
<p>X Values: 4,5,6
Y Values: 5,6</p>
<p>Since you’re only finding the minimum value which doesn’t include the actual min. It’s ok to say X = 3 and Y = 7
x-y</p>
<p>Min:
3-7 = -4</p>
<p>Max
7-3 = 3</p>
<p>When we write it out we DON’T include -4 and 3</p>
<p>So -4 < x-y < 3 is the right answer.</p>
<p>EDIT: someone already beat me to it :p</p>