We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
74
3
avatar

Given positive integers x and y such that 2x^2*y^3+4y^3=149+3x^2, what is the value of x+y?

 Jul 12, 2019
 #1
avatar
0

Anyone?

 Jul 12, 2019
 #2
avatar
0

x = 3  and  y = 2

 Jul 12, 2019
 #3
avatar+102386 
+2

2x^2*y^3+4y^3=149+3x^2

 

2y^3*x^2 - 3x^2 + 4y^3 - 149 = 0

 

(2y^3 - 3)x^2 + 4y^3 - 149   =  0

 

         √ [ - 4(2y^3 - 3)(4y^3- 149) ]         √ [ 4 (2y^3 - 3) (149 - 4y^3) ]                 

x =    ________________________  =    _________________________   =   

              2(2y^3 - 3)                                         2 ( 2y^3 - 3)                                         

 

 

       √ [ (2y^3 - 3) (149 - 4y^3)]                        √ [  (149 - 4y^3)]

=      ______________________    =             _____________

             (2y^3  - 3)                                                 √ (2y^3 - 3)

 

 

 

Assuming that y is an integer > 1  ....    if y =  2.... then x  =   √[ 117 / 13]  =  √9  =  3

 

So..(x, y)  = (3, 2)

 

 

cool cool cool

 Jul 13, 2019

18 Online Users

avatar
avatar