Question

Tolong di jawab , besok di kumpulkan

Tentukan titik potong garis-garis berikut
1. Y = 8x + 5 dan y = x - 9
2. Y = (-3x) +7 dan y = 2x + 12

Answer 1

1. y = y
8x + 5 = x - 9
8x - x = -9 - 5
7x = -14
x = -14 : 7
x = -2

y = x - 9 = -2 - 9 = -11

Titik potong (-2,-11)

2. y = y
-3x + 7 = 2x + 12
7 - 12 = 2x + 3x
-5 = 5x
x = -5 : 5
x = -1

y = 2x + 12= 2 × (-1) + 12 = -2 + 12 = 10

Titik potong (-1,10)