maths問題!!!急!!!!!!!急!!!!!!!!!!!!!!!

As the difference of any two successive members of the pattern is a constant (－2), the pattern is an arithmetic progression or arithmetic sequence.

The initial term of the arithmetic progression is 2 and the common difference of successive members is －2. Therefore, the nth term of the sequence is given by

a(n)＝2＋(n－1)(－2)＝4－2n

where n＝1,2,3,...

2-2=0
0-2=-2
-2-2=-4
-4-2=-6
-6-2=-8
......
希望可以帮到你拉!

有絛FORMULA你用既

T(n)=a+d(n-1)

then a=the first number=2

d=-2

T(n)=2-2(n-1)

=4-2n

可以睇到係每個數減2

由於第一個TERM係2, 所以PATTERN 可以用一條式總結: 2+(-2)(n-1)

T(1)2=2-2x(1-1)
T(2)=0=2-2x(2-1)
T(3)=-2=2-2x(3-1)
T(4)=-4=2-2x(4-1)
T(5)=-6=2-2x(5-1)
T(n)=2-2(n-1)=2-2n+2=4-2n