F.1兩條數學問題~~十萬火急~~10點!!幫幫手!!

2009-11-17 7:24 am

1.simplify(簡化)(俾埋steps):(上面係分子,下面係分母,唔好意思,冇左條分線)
15XpXqXpXp二次方X4XqXq三次方
pXqXqX6Xq二次方XpXq二次方

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2.Write down an algebraic expression to represent the nth term of each sequence.
7,2,-3,-8,-13 ......

The nth term
=________________

回答 (1)

sir

2009-11-17 7:56 am

✔ 最佳答案

1) 15 x p x q x p x p^2 x 4 x q x q^3
p x q x q x 6 x q^2 x p x q^2

= 15 x 4 x p x p x p^2 x q x q x q^3
6 x p x p x q x q x q^2 x q^2

= 60 x p^4 x q^5
6 x p^2 x q^6

= 10 p^2
q

2) 7, 2, -3, -8, -13, ...

This is a A.P. with common difference -5

The nth term

= First Term + (n - 1) x common difference

= 7 + (n - 1) (-5)

= 12 - 5n

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