Tolong kak soal persamaan kuadrat beserta caranya ya

Jawaban:

gunakanlah cara diatas pada gambar

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Penjelasan dengan langkah-langkah:

cara memfaktorkan

no. 1 belum ketemu hasilnya

2)

x² + 11x + 30 = 0

(x + 5)(x + 6 ) = 0

(x + 5) = 0

x = – 5

(x + 6) = 0

x = – 6

HP = { -5. – 6 }

3)

2x² +5x – 12 = 0

(2x – 3)(x + 4) = 0

(2x – 3) = 0

2x = 3

x = 3/2

(x + 4 ) = 0

x = – 4

HP = { 3/2 , – 4}

cara melengkapi kuadrat

4)

x² – x – 20 = 0

(x – 1/2)² – (1/2)² – 20 = 0

(x – 1/2)² – 1/4 – 20 = 0

(x – 1/2)² – 1/4 – 80/4 = 0

(x – 1/2)² – 81/4 = 0

(x – 1/2)² = 81/4

(x – 1/2) = √81/4

(x – 1/2) = ± 9/2

x = ± 9/2 + 1/2

x₁ = 9/2 + 1/2

x₁ = 10/2

x₁ = 5

x₂ = -9/2 + 1/2

x₂ = -8/2

x₂ = – 4

HP = { -4, 5 }

5)

x² + 2x – 8 = 0

(x + 1)² – 1² – 8 = 0

(x + 1)² – 1 – 8 = 0

(x + 1)² – 9 = 0

(x + 1)² = 9

x + 1 = √9

x + 1 = ± 3

x = ± 3 – 1

x₁ = 3 – 1

x₁ = 2

x₂ = -3 – 1

x₂ = – 4

HP = { -4 , 2) }

6)

2x² – 2x – 4 = 0…..sederhanakan bagi 2

x² – x – 2 = 0

(x – 1/2)² – (1/2)² – 2 =0

(x – 1/2)² – 1/4 – 2 = 0

(x – 1/2)² – 1/4 – 8/4 = 0

(x – 1/2)² – 9/4 =0

(x – 1/2)² = 9/4

(x – 1/2) = √9/4

x – 1/2 = ± 3/2

x = ± 3/2 + 1/2

x₁ = 3/2 + 1/2

x₁ = 4/2

x₁ = 2

x₂ = – 3/2 + 1/2

x₂ = – 1

HP = { -1, 2 }

pakai rumus

x₁,₂ = (-b ± √D)/2a

D = b² – 4ac

7)

x² – 10x – 24 = 0

a = 1 , b = -10, c = – 24

D = (-10)² -4(1)(-24)

D = 100 + 96

D = 196

x₁,₂ = -(-10) ± √196)/2(1)

x₁,₂ = (10 ± 14)/2

x₁,₂ = 5 ± 7

x₁ = 5 + 7 = 12

x₁ = 5 – 7 / = -2

HP = { -2, 12 }

8)

x² + 6x x + 5 = 0

a = 1 , b = 6, c = 5

D = (6)² -4(1)(5)

D = 36 – 20

D = 16

x₁,₂ = (-6) ± √16)/2(1)

x₁,₂ = (- 6 ± 4)/2

x₁,₂ = -3 ± 2

x₁ = – 3 + 2

x₁ = – 1

x₂ = – 3 – 2

x₂ = – 5

HP = { – 5, – 1}

9)

2x² + 5x – 7 = 0

a = 2, b = 5, c = – 7

D = (5)² -4(2)(-7)

D = 25 + 56

D = 81

x₁,₂ = (-5) ± √81)/2(2)

x₁,₂ = (- 5 ± 9)/4

x₁,₂ = – 5/4 ± 9/4

x₁ = – 5/4 + 9/4

x₁ = 4/4

x₁ = 1

x₂ = -5/4 – 9/4

x₂ = – 14/4

x₂ = – 7/2

HP = { – 7/2, 1}