TO THE RESOLUTION ÔF PROBLEMS»
109
Will be x -f l: moreover, the whole price of the pep«
per will be crowns, and that of the ginger
therefore, by the question,
120
x
120
x -f 1
rr 6; whence
120.r 120— 120a: — 6r* + 6a?, and therefore x z + x
— 20; which, solved, gives x = 4 =r the pounds of
pepper, and x -f l — 5 — those of ginger»
PROBLEM LV.
To find three numbers in arithmetical progression„
whereof the sum of the squares shall be 1232 (aJ, and
the square of the mean greater than the product of the
two extremes by 16 (bj.
Let the mean be denoted by x, and the common dif
ference by y; then the numbers themselves will bear—'y t
x 4 and x -4- y; and so, by the problem, we shall have
these two equations,
x —yf + x 1 + x + y\~ zz a, and
x* — x — y x x + y + b: these, contracted, become
3x z + 2if zz «, and x z zz x z — y z + b; from the latter
whereof we get y 2 — b zz 16; and consequently y zz
\/b — 4; which, substituted for y in the former, gives
3x* -f 2b zz a; whence x 1
and therefore
20; so that the three required
numbers are 16, 20, and 24.
v s 16* + 20 x + 24 7 rr 1232,
1 ° r j 20 7 — 16 X 24 ~ 16.
PROBLEM LVI*
To find two numbers whose difference shall be 10 f aj t
and if600 fbj be divided by each of them, the difference
of the quotients shall also be equal to 10 f a J>
The lesser number being represented by x, the greater
will be represented by x -f a; and therefore, by the prob
lem ~ —7— = a; which, freed from fractions.
x x -f a