Question

a) -x²+2x=0 b) x²-4=0 c) 2x-10=x+5 d) x²-2x- 3=0​
É URGENTE

Answer 1

Resposta:

–x² + 2x = 0

x.(–x + 2 = 0

x1 = 0

–x + 2 = 0

(–x = –2).(–1)

x = 2

Exercício A: S = {0, 2}

x² – 4 = 0

x² = 4

x = √4

x = 2

Exercício B: S = {2}

2x – 10 = x + 5

– 10 – 5 = x – 2x

(– x = – 5).(–1)

x = 5

Exercício C: S = {5}

x² – 2x – 3 = 0

∆ = b² – 4ac

∆ = (–2)² – 4.1.(–3)

∆ = 4 + 12

∆ = 16

x = – b ± √∆/2a

x = – 2 ± √16/2a

x = – 2 ± 4/2

x1 = – 2 – 4/2 = – 3

x2 = – 2 + 4/2 = 1

Exercício D: S = {– 3, 1)