Question

Solve algebraically: 4x^2-9y^2=108 xy= -12
[please help] medal given.

Answer 1

xy =-12 (no need to set up condition that x , y not =0)
---> \[y=\frac{-12}{x}\]---> \[y^2 = \frac{144}{x^2}\]
replace into the first equation to get \[4x^2-9(\frac{144}{x^2})=108\]
---> \[4x^4 - 1296 = 108 x^2\]
\[4x^4 -108x^2 -1296 =0\] I dont' think it's hard for you from this

Answer 2

got it! thanks @Loser66