r -\- I x P 
r — 1 X2» 
[ 49 6 ] 
; and it remains, only, to prove the equa- 
lity of the expreflions, 
i — -T p 
— 1- — and — - 
r — i 2 n r — I 
r + i * P 
i x 2 n 
, which may be done as follows : 
Put 
i— r P 
11 
+ 
P_ 
2 n 
r — i 
= JV. 
Then i P 4- 
n 2 n 
P = r — i xiVj 
But, becaufe 
And 
Therefore 
9 
Whence 
2 r 
m 
r 2 r 
n 2 n 
r — i r-h I 
2 tz 
r4-i 
2 72 
2 n 
P = r — I x A - , 
r-f i x P 
r — i 
= N: 
r 1X272 
And the equality of the two expreflions is evident : 
From whence it appears, that the value of an an- 
nuity for life (fecured by land) might have been 
found, exactly enough, without the afliftance of flu- 
xions. 
The 
