tolonglah dijawab dg caranya..

Kelas 10 Matematika
Bab Persamaan dan Fungsi Kuadrat

1] x - 3 = a
x = a + 3

x² + 2x - 6 = 0
(a + 3)² + 2(a + 3) - 6 = 0
a² + 6a + 9 + 2a + 6 - 6 = 0
a² + 8a + 9 = 0
x² + 8x + 9 = 0

✩✩ C ✩✩

2] f(x) = 2x² - 9x + 10

Memotong sumbu y, maka x = 0

y = 0 - 0 + 10
y = 10

(0, 10)

Memotong sumbu x, maka y = 0

f(x) = 0
2x² - 9x + 10 = 0
(2x - 5) (x - 2) = 0
2x - 5 = 0
2x = 5
x = 5/2 → (5/2, 0)

x - 2 = 0
x = 2 → (2, 0)

(2, 0), (5/2, 0), (0, 10)

✩✩ D ✩✩