Question

Resolva a equação do 2 grau:
( x-2).(x+2)-(x-1)2= x2-8

Answer 1

(x-2).(x+2) -(x-1)² = x²-8

x²-4 -(x²-2x+1) = x²-8

x²-4 -x²+2x-1 -x²+8=0

-x² +2x +3 = 0 ==> *(-1)

x² -2x -3 = 0

∆= (-2)² -4.1.(-3)=4+12=16 => √∆=4

x = -b±√∆/2a

x = 2±4/2.1

x' = 2+4/2 = 6/2 = 3 ✓

x" = 2-4/2 = -2/2 = -1 ✓