Answer
$(\sqrt{11},-4),(-\sqrt{11},-4)$
Work Step by Step
If we add $-1.5$ times the second equation to the first one, we get:
$-3.5y=14\\y=-4$
Plugging this back into the first one, we get:
$3x^2+4(-4)=17\\3x^2=33\\x^2=11\\x=\pm\sqrt{11}$
Hence, the solutions are:
$(\sqrt{11},-4),(-\sqrt{11},-4)$