0Đ. B, 9X2 + 6X – 8 = 9X2 – 6X + 12X – 8 0,5Đ. = ( 3X – 2)( 3X + 4)...

1, - DE DAP AN THI HSG TOAN 67 8 HUYEN THANH OAI
Lớp 6 Toán DE DAP AN THI HSG TOAN 67 8 HUYEN THANH OAI

1,0đ.

b, 9x

2

+ 6x – 8 = 9x

2

– 6x + 12x – 8

0,5đ.

= ( 3x – 2)( 3x + 4) = 0

-> x =

32

, x =

−34

2

1 2

2

1

x

 