Помогите добрые люди) (5х-2)(3х+2)=0

Question

Помогите добрые люди)
(5х-2)(3х+2)=0

Answer 1

15х^2+10x-6x-4=0
15х^2+4x-4=0
D=16+4*4*15=256
x1=(-4+16)/30=12/30=4/10=0.4
x2=(-4-16)/30=-20/30=-2/3