a. x^2 + 8x + 15 = 0
b. x^2 + 8x – 15 = 0
c. x^2 – 8x + 15 = 0
d. x^2 – 8x – 15 = 0
e. x^2 + 8x + 8 = 0
Tentukan persamaan kuadrat jika diketahui akar akarnya -3 dan -5
Jawab:
A
Penjelasan dengan langkah-langkah:
x1 = -3
x2 = – 5
persamaan kuadrat
x² – (x₁+x₂)x + (x₁.x₂) = 0
x² – (-3+(-5))x + (-3)(-5) = 0
x² +8x + 15 = 0
(x – (-3)) (x – (-5) = 0
(x + 3) (x + 5) = 0
x² + 5x + 3x + 15 = 0
x² + 8x + 15 = 0