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 Post subject: Algebra Book Question 91, Page 114
PostPosted: Sat Apr 09, 2011 11:58 am 
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Joined: Fri Mar 18, 2011 12:27 pm
Posts: 17
I read another explaination for this question but it is still not clear to me.
Question: If x and y are integers and y = lx+3l + l4-xl, does y equal 7?
1. x < 4
2. x > -3

I thought it would be E. I don't understand the relationship between the two points. The answer is C.

Please help!


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 Post subject: Re: Algebra Book Question 91, Page 114
PostPosted: Sun Apr 10, 2011 8:14 pm 
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Posts: 497
If x and y are integers and y = lx+3l + l4-xl, does y equal 7?
1. x < 4
2. x > -3

Easiest way to see this might be to plug in some numbers.

Let's start with statement 1.
And let's try x=3.
This makes lx+3l + l4-xl = |3+3| + |4-3| = 6 + 1 = 7 ==> so in this case, yes, y=7
Now, let's try something much smaller.
x=-5
lx+3l + l4-xl = |(-5) + 3| + |4-(-5)| = |-2| + |9| = 2 + 9 = 11 ==> and in this case, no, y is not =7.
So this statement isn't sufficient.

Now let's try statement 2.
We can still use x=3 from above, and get to y=7.
Let's also look at x=5
lx+3l + l4-xl = |5+3| + |4-5| = 8 + 1 = 9 ==> here, y isn't 7, so this statement isn't sufficient.

However, you will find that for all values between -3 and +4, we will have y=7, so our answer is C.

Veritas Help


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 Post subject: Re: Algebra Book Question 91, Page 114
PostPosted: Mon Apr 11, 2011 9:03 am 
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Joined: Fri Mar 18, 2011 12:27 pm
Posts: 17
I understand now. It's definitely a lot easier than I thought!!

Thank you!


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