Tentukan himpunan persamaan berikut dengan menggunakan kuadrat sempurna 2x^2 + 6x - 20 = 0

Kelas : IX SMP
Mapel : Matematika 
Materi : Persamaan Kuadrat
Indikator : Mencari HP Persamaan Kuadrat

Langkah Penyelesaian dan Jawaban :
2x² + 6x - 20 = 0
------------------------ ÷ 2
x² + 3x - 10 = 0

x² + 3x = 10
(x + 3/2)² = 10 + (3/2)²
(x + 3/2)² = 10 + 9/4
(x + 3/2)² = 49/4
x + 3/2 = +/- √(49/4)

x + 3/2 = √(49/4)
x + 3/2 = 7/2
x = 7/2 - 3/2
x = 4/2
x = 2

x + 3/2 = - √(49/4)
x + 3/2 = - 7/2
x = - 7/2 - 3/2
x = - 10/2
x = - 5

HP = {- 5, 2}

2x²+6x-20. = 0
______________ : 2
x² + 3x - 10. = 0
x² + 3x = 10
x² + 3x+(³/2)² = 10+ (3/2)²
(x+ ³/2) ² = 10+ 9/4
= 40/4 + 9/4
= 49/4
(x + ³/2) = 7/2 dan -7/2

x+ ³/2,= 7/2
x = 7/2 - ³/2
= 4/2
= 2

x+ ³/2 = -7/2
x = -7/2 - ³/2
= -10/2
= -5

Hp (-5 , 2)