Chúc bn hc tốt !!!
Bài 1:
a, 4x ²-4x+1-y ² = (4x ² - 4x + 1) - y ²
= (2x - 1)² - y²
= (2x - 1 - y)(2x - 1 + y)
b, 4x ³ - 4x ² - 9x + 9 = (4x ³ - 4x ²) - (9x - 9)
= 4x(x - 1) - 9(x - 1)
= (x - 1)(4x - 9)
c, 16x ²-2x-3 = 16x² - 8x + 6x - 3
= (16x² - 8x) + (6x - 3)
= 8x(2x - 1) + 3(2x - 1)
= (2x - 1)(8x + 3)
Bài 2:
a, (x + 3 ) ² - (x - 1)(x + 1) = 0
↔ x² + 6x + 9 - x² + 1 = 0
↔ 6x + 10 = 0
↔ 6x = -10
→ x = -5/3
b, (x - 2)² - 3x + 6 = 0
↔ (x - 2)² - (3x + 6) = 0
↔ (x - 2)² - 3(x + 2) = 0
↔ (x - 2)(x - 2 - 3) = 0
⇔ (x - 2)(x - 5)
TH1 : x - 2 = 0
↔ x = 0 + 2 = 2
TH2: x - 5 = 0
↔ x = 0 + 5 = 5
@FanMaple
#Bạn bè là tất cả
