Question

Olá,preciso de ajuda na seguinte questão da imagem,Questão 1.

Answer 1

1-a) x²-6x = 0
x·(x-6) = 0
→ x = 0
→ x-6 = 0 ⇒ x = 6

S = {0,6}

b) x²-16 = 0
x² = 16
x = +-√16
→ x = 4
→ x = -4

S = {-4,4}

c) x²-1 = 0
x² = 1
x = +-√1
→ x = -1
→ x = -1

S = {-1,1}

d) x²+x = 0
x·(x+1) = 0
→ x = 0
→ x+1 = 0 ⇒ x = -1

S = {-1,0}

e) 7x²-2x = 0
x·(7x-2) = 0
→ x = 0
→ 7x-2 = 0 ⇒ 7x = 2 ⇒ x = 2/7

S = {0, 2/7}

f) x²+49 = 0
x² = -49
x = √-49

S = {   }

g) 8x²-6x = 0
2x·(4x-3) = 0
→ 2x = 0 ⇒ x = 0
→ 4x-3 = 0 ⇒ 4x = 3 ⇒ x = 3/4

S = {0, 3/4}

h) -4x²+12x = 0
4x·(-x+3) = 0
→ 4x = 0 ⇒ x = 0
→ -x+3 = 0 ⇒ x = 3

S = {0,3}

i) 6x²-x = 0
x·(6x-1) = 0
→ x = 0
→ 6x-1 = 0 ⇒ 6x = 1 ⇒ x = 1/6

S = {0, 1/6}

j) x²-18 = 0
x² = 18
x = +-√18

18 | 2
9 | 3
3 | 3
1

x = +-√(2·3²)
→ x = 3√2
→ x = -3√2

S = {-3√2, 3√2}

l) 16y² = 9
y² = 9/16
y = +-√(9/16)
→ y = 3/4
→ y = -3/4

S = {-3/4, 3/4}

m) -20x²-5x = 0
5x·(-4x-1) = 0
→ 5x = 0 ⇒ x = 0
→ -4x-1 = 0 ⇒ 4x = -1 ⇒ x = -1/4

S = {-1/4, 0}