Math, asked by udaysingh3, 1 year ago

find value of 27x^3+8y^3 if 3x+2y=14 and xy= 8

Answers

Answered by abhi569
0
3x+2y = 14

cube on both sides,

(3x+2y)^2 = 14^3

= 27x^3 +8y^3 +3(3x*2y)[3x+2y] = 2744

=27x^3 + 8y^3 + 18(8)[14] = 2744

=27x^3 + 8y^3 + 2016 = 2744

 = 27x^3 +8y^3 = 2744 - 2016

=27x^3 +8y^3 = 728




i hope this will help you 




- by ABHAY
Answered by YaminiRathi
0
27x³+8y³= (3x)³ + (2y)³
= (3x+2y)³-3(3x*2y)(3x+2y)
= (14)³-3(6*8)(14)
= 2744 - 2016
= 728
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