Помогите -5y(y+3)+(y-4)

Question

Помогите -5y(y+3)+(y-4)

Answer 1

-5у²-15у+у-4=-5у²-14у-4=-(5у²+14у+4)=-5((y-(-7+√29)(y-(-7-√29))

5y²+14y+4=0
D=196-80=116
√D=√116=2√29
y1=(-14+2√29)/10=(-7+√29)/5
y2=(-7-√29)/5