# Number patterns and sequences - Tn Term

#### JanleyKrueger

##### New member
The number sequence is as follows:

3x+5y; 5x; 7x-5y; 9x-10y.....

I need to formulate a general term - Tn=T1+d(n-1)
In the above sequence I have no idea what.
I also think this sequence is non linear.
Please help with a solution
Thanks

#### HallsofIvy

##### Well-known member
MHB Math Helper
If it is non- linear then it cannot be written in that form! Taking $$T_1= 3x+ 5y$$, $$T_2=5x$$, $$T_3= 7x-5y$$, and $$T_4= 9x-10y$$, then you want $$T_2= 5x= 3x+ 5y+ d$$ so $$d= 2x- 5y[tex]. But then you want [tex]T_3= 7x- 5y= 3x+ 5y+ 2d$$ so $$d= (4x- 10y)/2= x- 10y$$. Those are not the same so this sequence cannot be written in that way.

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