-5x^2+2x+16=(x-2)^2

Question

-5x^2+2x+16=(x-2)^2

Answer 1

-10х+2х+16=2х-4

-10х+2Х-2Х=-20

-10Х=-20

Х=-20:(-10)

Х=2 

Answer 2

-5x^2+2x+16-x^2+4x-4

-6x^2+6x+12=0

x^2-x-2=0

D=9

x1=2

x2=-1