(x-3y)(3y+x)=(x-3y)(x+3y)=x^2-9y^2
(x-2)^2+8x=(x-1)(1+x)
x^2-4x+4+8x=
x^2-4x+4+8x-x^2+1=0
4x+5=0
4x=-5
x=-5/4
x=-1,25
1) (x-3y)(3y+x)=x^2-9y^2
2) (x-2)^2+8x=(x-1)(1+x)
(x-2)^2+8x=x^2-1
x=-1.25
(x-3y)(3y+x)=(x-3y)(x+3y)=x^2-9y^2
(x-2)^2+8x=(x-1)(1+x)
x^2-4x+4+8x=
x^2-4x+4+8x-x^2+1=0
4x+5=0
4x=-5
x=-5/4
x=-1,25
1) (x-3y)(3y+x)=x^2-9y^2
2) (x-2)^2+8x=(x-1)(1+x)
(x-2)^2+8x=x^2-1
x^2-4x+4+8x-x^2+1=0
4x+5=0
4x=-5
x=-1.25