Question

Tentukan himpunan dari:
a. X²-5x-14=0
b. 12X²-5x-2=0
Dengan cara pemfaktoran dan melengkapi kuadrat

Answer 1

A) x² -5x -14 = 0 (pemfaktoran)
a = 1 b = -5 c = -14
a.c = -14 = 2 + (-7)= -5 (b)
x² -5x -14 = x² - (2x + 7x) - 14
= (x² - 2x) + (7x - 14x)
= x(x - 2) + 7(x - 2)
= (x + 7) (x - 2)

b) 12x² - 5x - 2 = 0 (pemfaktoran)
a = 12 b = -5 c = -2
a.c = -24 = 3 - 8 = -5 (b)
12x² - 5x - 2 = 12x² - (3x + 8x) - 2
= (12x² - 3x) + (8x - 2)
= 12x (x - 4) + 8 (x - 4)
= (12x + 8) (x-4)