( 63 ) 
After multiplying the 2°¢ equation by A and the 3rd by B, 
we can add them to the first equation, and then we conclude to: 
ny st aa asa AT =, e (a) 
x 
m!' 
ee —— Am' -|- EE ZE 0, 5 . . . . (/?) 
y 
y —An' + B pr an ’ (y) 
t U? m'2 ni ) 
ae : ee 
oe g" ( (az vas)? (ay vis"? a (az eee ed 0 
U2 + mn? reek EREN oe REN 
Wee ee Pee gle ea nay Ou ae ea 
From these equations and from (53) and (55) we have to eliminate 
A, B, U, m',n' and s". We can eliminate A and B by substituting 
N', w' and v' from (@), (7) and (y) in (G) and (55). 
We find: 
If we substitute this in (@), (7) and (y), we find: 
yy o” he ri sl Lt 
az v—o2 arts"? i : i 
u gy" m! ty 
eee tat gre ° ° e ° ° (57) 
y Sf ed Wd 
yv! o” ze n' rl 7 
az vg"? aa az pes"? ME Gt Th hl (58) 
If we multiply (56) by En ei and 
2e 
(58) by Amai and add, we find after some reduction: 
g 
