Question

30 х+120+12х-2х²-8х=0

Answer 1

$30x+120+12x-2x^{2}-8x=0\\-2x^{2}+34x+120=0|:(-2)\\x^{2}-17x-60=0\\D:289+240=529\\x_1,_2= \frac{17\pm 23}{2}\\x_1=20\\x_2=-3$