Difference between revisions of "2017 UNM-PNM Statewide High School Mathematics Contest II Problems/Problem 5"

(Created page with " == Problem == Find all real triples <math>(x,y,z)</math> which are solutions to the system: <math>x^3 + x^2y + x^2z = 40</math> <math>y^3 + y^2x + y^2z = 90</math> <math...")
 
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== Solution==
 
== Solution==
 
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There are <math>3</math> solutions <math>(2,3,5)</math> or <math>(-\sqrt[3]{\frac{40}{3}} ,\sqrt[3]{45},\sqrt[3]{\frac{5^4}{3}})</math> or <math>(\sqrt[3]{20},-\frac{3\sqrt[3]{20}}{ 2} , \frac{5\sqrt[3]{20}}{ 2})</math>
 
 
  
 
== See also ==
 
== See also ==

Latest revision as of 04:14, 19 January 2019


Problem

Find all real triples $(x,y,z)$ which are solutions to the system:

$x^3 + x^2y + x^2z = 40$

$y^3 + y^2x + y^2z = 90$

$z^3 + z^2x + z^2y = 250$

Solution

There are $3$ solutions $(2,3,5)$ or $(-\sqrt[3]{\frac{40}{3}} ,\sqrt[3]{45},\sqrt[3]{\frac{5^4}{3}})$ or $(\sqrt[3]{20},-\frac{3\sqrt[3]{20}}{ 2} , \frac{5\sqrt[3]{20}}{ 2})$

See also

2017 UNM-PNM Contest II (ProblemsAnswer KeyResources)
Preceded by
Problem 4
Followed by
Problem 6
1 2 3 4 5 6 7 8 9 10
All UNM-PNM Problems and Solutions