SOLUTION: 1. If x + y = 17 and x^2 + y^2 = 167, what is the value of 3xy? 2. If x + y = 13 and xy = 17, what is the value of 2(x^2+y^2)? 3. If r^2 + s^2 = 18, and r + s = 5, what is th

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Question 1168764: 1. If x + y = 17 and x^2 + y^2 = 167, what is the value of 3xy?
2. If x + y = 13 and xy = 17, what is the value of 2(x^2+y^2)?
3. If r^2 + s^2 = 18, and r + s = 5, what is the value of 4rs?
4. If x + y = 17 and x^2 + y^2 = 167, what is the value of 3xy?

Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39620)   (Show Source): You can put this solution on YOUR website!







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What about #2 and #3?

Use #1, done here already, as a guide. Think! #1 and #3 are similar.





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#2, just a start,


substitute using the other given equation,...
...

Answer by ikleyn(52798)   (Show Source): You can put this solution on YOUR website!
.
1. If x + y = 17 and x^2 + y^2 = 167, what is the value of 3xy?
2. If x + y = 13 and xy = 17, what is the value of 2(x^2+y^2)?
3. If r^2 + s^2 = 18, and r + s = 5, what is the value of 4rs?
4. If x + y = 17 and x^2 + y^2 = 167, what is the value of 3xy?
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Notice that   #4  is identical to   #1,

so I do not understand for what reason you request two identical problems in one post.


I only can suggest that you do not read what you post,  at all.


If you have another explanation,  feel free to disprove my suggestion . . .



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