hi
i find these really difficult
Solve y = 2x^2 + 3 and x^2– xy= –4 simultaneously
i know ir shouldnt be, i just think they are[/FONT]
$\displaystyle x \in R$
$\displaystyle \left\{\begin{array}{cc}y=2x^2+3 \\x^2-xy=-4 \end{array}\right.$
$\displaystyle \left\{\begin{array}{cc}y=2x^2+3 \\x^2-x(2x^2+3)=-4 \end{array}\right.$
$\displaystyle \left\{\begin{array}{cc}y=2x^2+3 \\(x-1)(2x^2+x+4)=0 \end{array}\right.$
$\displaystyle \left\{\begin{array}{cc}y=2+3 \\x=1 \end{array}\right.$
$\displaystyle \left\{\begin{array}{cc}y=5 \\x=1 \end{array}\right.$