2y^2-50y=75-3y
2y^2-47y-75=0
D=47^2+4*2*75=2809
y1=(47-53)/2*2=-1.5
y2=(47+53)/2*2=25
x² + 4x - 2 = (x² + 4x + 4) - 4 - 2 = (x + 2)² - 6 = (x + 2)² - (√6)² =
= (x + 2 + √6)(x + 2 - √6)