Answer
$(\dfrac{12}{5},-\dfrac{29}{5})$, $(-2,3)$
Work Step by Step
After using the substitution method, we get
$x^2+(-2x-1)^2+3(-2x-1)=22$
or, $x^2+4x^2+4x+1-6x-3=22$
or, $5x^2-2x-24=0$
Thus, we have $(5x-12)(x+2)=0$
when $x=12/5$ then we have $y=-2(12/5)-1$
This gives: $y=-\dfrac{29}{5}$
when $x=-2$ then we have $y=-2(-2)-1$
This gives: $y=3$
Hence, our answers are: $(\dfrac{12}{5},-\dfrac{29}{5})$, $(-2,3)$
