Penjelasan dengan langkah-langkah:

Persamaan Kuadrat

Nomor (1)

x² + 12x + 20 = 0

x² + 10x + 2x + 20 = 0

x(x + 10) + 2(x + 10) = 0

(x + 2)(x + 10) = 0

x1 = -2 V x2 = -10

HP = { -2 , -10 }

Nomor (2)

x² - 10x + 16 = 0

x² - 8x - 2x + 16 = 0

x(x - 8) - 2(x - 8) = 0

(x - 2)(x - 8) = 0

x1 = 2 V x2 = 8

HP = { 2 , 8 }

Nomor (3)

x² + 12x - 48 = 0

a = 1 , b = 12 , c = -48

x1,2 = (-b ± √b² - 4ac)/2a

x1,2 = (-12 ± √12² - 4(1)(-48))/2(1)

x1,2 = (-12 ± √(144 + 192)/2

x1,2 = (-12 ± √336)/2

x1,2 = (-12 ± 4√21)/2

x1 = (-12 + 4√21)/2 = (-6 + 2√21)

x2 = (-12 - 4√21)/2 = (-6 - 2√21)

Nomor (4)

x² - x - 72 = 0

x² - 9x + 8x - 72 = 0

x(x - 9) + 8(x - 9) = 0

(x + 8)(x - 9) = 0

x1 = -8 V x2 = 9

HP = { -8 , 9 }