Question

doar punctul b) va rog mult

Answer 1

scoatem y din a 2a:

2y^2+3xy+1=0

delta=9x^2-4*2*1=9x^2-8

y1= $\frac{-3x+ \sqrt{9x^2-8} }{4}$

y2=$\frac{-3x- \sqrt{9x^2-8} }{4}$

scoatem y din prima :

y=$\frac{-8+x^2}{7x}$

egalam y1 cu y si aflam x-urile:

$\frac{-3x+ \sqrt{9x^2-8} }{4}$ = $\frac{-8+x^2}{7x}$

cativa pasi de aranjare:

$-3x+ \sqrt{9x^2-8}= \frac{-32+4x^2}{7x}$

$-21x^2+7x \sqrt{9x^2-8}=-32+4x^2$

$-25x^2+32=-7x \sqrt{9x^2-8}$

ridicam la patrat

$625x^4+32*32-2*32*25*x^2=49x^2*9x^2-49x^2*8$

$184x^4-1208x^2+1024=0$

notam x^2=t

$184t^2-1208t+1024=0$

rezolvam ec. cu delta

delta=705600

=> radical din delta = 840