Question

Equações de 2° grau
a) (x-3) (x+2) = -4
b) (x-3)² = 16
c) (x-1)² + 8 (x+1) = 0

Answer 1

a)x² +2x-3x-6 =-4

x² - x - 2 = 0

(0-1² - 4.1.(-2) = Δ

1+8 = 9 = Δ

-b+-√Δ/2a

1+-√9/2

(l) 1+9/2 = 10/2 = 5

(ll) 1-9/2 = 8/2 = 4

b) x² -3x -3x +9-16 = 0

x² -6x - 7 = 0

(-6)² -.1.(-7) = Δ

36 + 28 = 64 = Δ

-(-6) +-√64/2

(l) 6+8/2 = 14/2 = 7

(ll) 6-8/2 = -2/2= -1

c) (x-1).(x-1) + 8 (x+1) =0

x² -x -x +1 +8x +8 = 0

x² +6x +9 = 0

62 - 4 . 1 .9 = Δ

36 - 36 = 0 = Δ

-6 +- √0/2

(l) e (ll) -6/2 = -3