■-'ft:'',
INDETERMINATE PROBLEMS.
191
to be
inti
i, an-
iftfw,
’ thick
— 3J5
= 138
tbetf’O*
PROBLEM XI.
If 5x + 7y + 11 z — 224; it is required to find all
the possible values of x, y, and z, in whole numbers.
In this, and other questions of the same kind, where
you have three or more indeterminate quantities and
only one equation, it will be proper, first of all, to
find the limits of those quantities. Thus, in the pre
sent case, because x is — — — tLlj. and because
the least values of y and z cannot (by the question) be
less than unity, it is plain that x cannot be greater than
004 n 1J
— , or 41 : and, in the same manner it will
appear that y cannot be greater than 29, nor z greater
than 19 ; which therefore are the required limits in this
,, . 224 —7y — 112
case. Moreover, since x is = ;
5
1 + 2 y +
45
nifest that
2 y 4-2+1
— a whole number, it is ma-
must also be a whole number:
let z + l be therefore considered as a known quan
tity, and let the same be represented by b, and then
2 y + b
the last expression will become
from which
by proceeding as above, we shall get y — 2b — 22
+ 2; whence the corresponding value of x comes out
~ 42 — 5z.
Let z be now taken =r 1, then will x — 37 and y
— 4; from the former of which values, let the co-efli-
cient of y be, continually, subtracted, aud to the latter,
let that of x be continually added, and we shall thence
have 37, 30, 23, 16, 9, and 2, for the successive values
of x; and 4, 9, 14, 19, 24, and 29, for the correspond
ing values of y: which are all the possible answers when
z — 1.
?;./f $4 : :