F.2 數學

1. 10u² - 11u - 6
=10u² + 4u - 15u - 6
=2u(5u + 2) -3(5u + 2)
=(5u + 2)(2u - 3)
2. 18 -123h -21h²
=18+3h-126h-21h²
=18+3h-(18+3h)7h
=(18+3h)(1-7h)
3. (2n + 3)² - 24n
=4n²+12n+9 -24n
=4n²-12n+9
=(2n-3)²

2007-05-11 20:07:25 補充：
你第二題我估你打錯係(21h²)唔係(21²)

1.10u^2-11u-6
(5u+2)(2u-3)
2.18-123h-441
-423-123h
-3h(141+41)
3.(2n+3)^2-24n
4n^2+12n+9-24n
4n^2-12n+9
(2n-3)^2

10u² - 11u -6 5 +2
2 -3
=(5+2)(2-3)_________十字相* ------------
4-15=-11
(2n + 3)² - 24n
=4n²+12n+9-24n
=4n²-12n+9
=(2n-3)²


Q2have some question.do you miss something?

1. 10u² - 11u -6
= ( 5u + 2 ) ( 2u-3 )..


2. 18 -123h -21h²
= ( 18 + 3h ) ( 1 – 7h )..


3. (2n + 3)² - 24n
= 4n² +12n + 9 – 24n
= ( 2n – 3 )²

1. 10u² - 11u -6
= ( 5u + 2 ) ( 2u-3 )


2. 18 -123h -21h²
= ( 18 + 3h ) ( 1 – 7h )


3. (2n + 3)² - 24n
= 4n² +12n + 9 – 24n
= 4n² -12n + 9
= ( 2n – 3 ) ( 2n – 3 )
= ( 2n – 3 )²


^o^ ^o^ ^o^