Help please..........................

Algebra
Tutor: None Selected Time limit: 1 Day

Can someone help?

http://latex.artofproblemsolving.com/1/4/3/143f7adfe5dbde261026c5f2225c12460a5b25a3.png

May 31st, 2015

x³ = 20x + 7y 
y³ = 7x + 20y 

(x + y)³ = x³ + 3x²y + 3xy² + y³ 
(x + y)³ = x³ + y³ + 3xy(x + y) 
(x + y)³ = 27(x + y) + 3xy(x + y) 
(x + y)² = 27 + 3xy 
x² + 2xy + y² = 27 + 3xy 
x² + y² = 27 + xy 

(x - y)³ = x³ - 3x²y + 3xy² - y³ 
(x - y)³ = x³ - y³ - 3xy(x - y) 
(x - y)³ = 13(x - y) - 3xy(x - y) 
(x - y)² = 13 - 3xy 
x² - 2xy + y² = 13 - 3xy 
x² + y² = 13 - xy 

x² + y² = x² + y² 
thus 13 - xy = 27 + xy 
2xy = -14 
xy = -7

let me know if you have any questions thank you

May 31st, 2015

Did you know? You can earn $20 for every friend you invite to Studypool!
Click here to
Refer a Friend
...
May 31st, 2015
...
May 31st, 2015
Dec 5th, 2016
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer