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DividendeDiviseurReste24036.....................×240...36...×............×............
DividendeDiviseurReste410246.....................×410...246...×............×............
E.14
In
a
newly
built
house,
we
want
to
tile
the
floors
in
certain
rooms.
1
The
dining
room
floor
is
a
rectangle
of
length
4.54
m
and
width
3.75
m
.
We
want
to
tile
this
room
with
square
tiles
33
cm
square.
We
start
the
installation
with
a
ˇ
corner
ı
of
the
room
as
suggested
in
the
adjacent
figure.
Calculate
the
number
of
uncut
tiles
that
will
have
been
laid.
2
The
kitchen
floor
is
a
rectangle
of
length
4.55
m
and
width
3.85
m
.
We
want
to
tile
this
room
with
a
whole
number
of
square
tiles,
without
any
cutting.
a
Give
the
list
of
divisors
of
455
and
then
the
list
of
divisors
of
385.
b
Give
the
list
of
divisors
common
to
455
and
385.
c
What
is
then
the
largest
possible
side
of
the
square
tiles
to
be
used
to
tile
this
kitchen?
3
We
have
rectangular
tiles
of
length
24
cm
and
width
15
cm
.
a
Give
the
list
of
multiples
of
24
less
than
400,
then
the
list
of
multiples
of
15
less
than
400
b
Give
the
list
of
multiples
common
to
24
and
15,
less
than
400.
c
What
would
be
the
side
length
of
the
smallest
square
room
that
could
be
tiled
with
an
integer
number
of
such
tiles,
without
any
cutting?
E.3328
1
Using
Euclid’s
algorithm,
complete
the
table
below
to
determine
the
PGCD
of
the
numbers
240
and
36
:
2
Make
the
fraction
240
36
irreducible
by
performing
a
sin-
gle
simplification.
By
what
integer
have
you
simplified?
Justify
your
approach.
E.4995
1
Using
Euclid’s
algorithm,
determine
the
PGCD
of
the
integers
410
and
246
:
2
a
Simplify
the
fraction
246
410
.
b
Perform
the
following
calculations
:
246
410
−
8
5
;
1
246
−
1
410
E.3329
1
Calculate
the
Greatest
Common
Divisor
(PGCD)
of
496
and
806.
2
Write
496
806
as
an
irreducible
fraction.
3
Calculate
496
806
−
3
26
(we’ll
give
the
result
as
an
irreducible
fraction)
E.3749
Using
Euclid’s
algorithm,
determine
the
PGCD
of
the
integers
a
and
b
:
a
a
=
354
;
b
=
20
b
a
=
1
456
;
b
=
256
c
a
=
17
;
b
=
3941
d
a
=
256
419
;
b
=
3
866
E.6077
Consider
the
equation
(
E
)
:
44
·
x
+
35
·
y
=
2
x
∈
N
;
y
∈
N
1
a
Using
Euclid’s
algorithm,
show
that
the
integers
44
and
35
are
prime
to
each
other.
b
Determine
a
pair
(
x
0
;
y
0
)
verifying
the
relation:
44
·
x
0
+
35
·
y
0
=
1
2
Deduce
the
set
of
solutions
to
the
equation
(
E
)
.
3.
Integers,
PGCD,
PPCM
E.259
1
Give
the
product
decomposition
of
prime
factors
of
the
following
natural
integers
:
a
25
×
72
b
54
×
12
c
32
×
84
d
100
×
98
2
From
question
1
,
determine
:
a
The
PGCD
of
the
pair
(25
×
72
;
54
×
12)
;
b
The
PPCM
of
the
pair
(32
×
84
;
100
×
98)
of
natural
in-
tegers.
3
Use
a
divisor
tree
to
determine
the
set
of
divisors
of
the
integer
315.
E.277
1
Determine
the
decompositions
into
prime
factors
of
the
following
integers
:
A
36
×
54
b
125
×
134
c
280
×
24
2
Deduce
the
PGCD
and
PPCM
of
the
pair
(6720
;
16750)
of
natural
numbers.
https://chingmath.fr
chapExoCorrec/14
sacados/14
chapExoCorrec/3328
sacados/3328
DividendeDiviseurReste24036.....................×240...36...×............×............
chapExoCorrec/4995
sacados/4995
DividendeDiviseurReste410246.....................×410...246...×............×............
chapExoCorrec/3329
sacados/3329
chapExoCorrec/3749
sacados/3749
chapExoCorrec/6077
sacados/6077
chapExoCorrec/259
sacados/259
chapExoCorrec/277
sacados/277
4.
Unlimited
development
E.1822
Consider
the
geometric
sequence
(
u
n
)
with
first
term
u
0
=2
and
reason
3.
1
a
Determine
the
terms
u
1
,
u
2
,
u
3
and
u
4
.
b
Give
the
base
7
writing
of
u
2
.
c
Show
that
writing
in
base
7
is
105
7
.
d
To
obtain
the
base
7
writing
of
u
4
,
a
student
has
per-formed
the
multiplication
below.
Say
whether
or
not
he
is
right
and
explain
why.
1
0
5
×
3
3
1
5
2
a
Show
that
:
u
5
=486
.
b
Consider
the
function
f
,
taken
from
an
algorithm,
and
taking
as
argument
a
a
natural
number:
Function
f(a)
L
←
empty
list
x
←
a
As
long
as
x>0
r
←
remainder
of
the
division
euclidean
division
of
x
by
7
Add
r
at
the
top
of
the
list
L
x
←
q
End
While
Return
L
Complete
the
tablebelow
to
record
the
different
val-ues
taken
by
the
variables
of
function
f
when
calling
function
function
f
using
parameter
a
=486
:
r
q
L
x
Initialisation
vide
486
End
of
stage
1
End
of
stage
2
.
.
.
.
.
.
Explain
the
link
between
the
items
in
the
list
L
and
the
writing
of
u
5
in
base
7.
3
We
divide
the
term
u
10
of
the
sequence
(
u
n
)
by
some
in-teger.
We
obtain
the
quotient
Q
whose
decimal
writing
is
Q
=14.727
272
727
272
72
:::
writing
in
which
the
digits
7
and
2
repeat
to
infinity.
Let
(
v
n
)
be
the
geometric
sequence
of
first
term
0.72
and
reason
0.01
.
a
Calculate
v
0
+
v
1
+
v
2
b
We
pose
S
n
=
v
0
+
v
1
+
v
2
+
···
+
c
n
where
n
is
a
non-zero
natural
number.
c
Calculate
S
n
.
Deduce
lim
n
↦→
+
∞
S
n
.
d
Deduce
a
writing
of
0.727
272
:
:
:
where
the
digits
7
and
2
repeat
to
infinity
in
the
form
of
the
quotient
of
two
integers.
What
is
the
number
by
which
we
divided
u
10
?
5.
Bezout’s
theorem
and
Euclid’s
algorithm
E.3751
For
each
equation,
determine
a
pair
of
integer
solutions
(
u
;
v
)
:
a
354
·
u
+
49
·
v
=
1
b
34
·
u
+
57
·
v
=
1
E.3753
1
Determine
a
couple
(
x
;
y
)
of
integers
solutions
of
the
equation
:
56
·
x
+
45
·
y
=
1
2
Deduce
a
couple
(
x
;
y
)
’of
relative
integers
verifying
the
equality:
56
·
x
+
45
·
y
=
3
6.
Unclassified
financial
years
E.29
1
Without
the
calculator,
perform
the
Euclidean
division
of
372
by
15
.
2
With
the
calculator,
determine
the
Euclidean
division
of
37
852
by
23
.
3
a
2456
=
17
×
143
+
25
Deduce
the
Euclidean
division
of
2
456
by
17
.
b
32
247
143
=
225
+
72
143
Deduce
the
Euclidean
division
of
32
247
by
143
.
c
516
43
=
12
Deduce
the
Euclidean
division
of
516
by
43
.
d
674
24
=
28
+
1
12
Deduce
the
Euclidean
division
of
674
by
24
.
e
5460
63
=
86
+
2
3
Deduce
the
Euclidean
division
of
5
460
by
63
.
https://chingmath.fr
sacados/1822
chapExoCorrec/3751
sacados/3751
chapExoCorrec/3753
sacados/3753
chapExoCorrec/29
sacados/29
E.336
We
want
to
determine
the
sign
of
the
following
expressions
:
2
y
;
x
+
y
;
x
−
y
;
x
(2
y
−
1)
;
−
x
+
y
In
the
following
cases
:
x>
0
and
y>
0
:
Positive
Négatif
On
ne
peut
conclude
2
y
x
+
y
x
−
y
x
(2
y
−
1)
−
x
+
y
x>
0
and
y<
0
:
Positive
Négatif
On
ne
peut
conclude
2
y
x
+
y
x
−
y
x
(2
y
−
1)
−
x
+
y
E.5302
The
aim
of
this
exercise
is
to
prove
by
absurdity
that
there
are
infinitely
many
prime
integers
of
the
form
4
n
−
1
,
where
n
is
an
element
of
N
∗
(set
of
non-zero
nat-ural
numbers)
.
1
Let
E
be
the
set
of
prime
integers
of
the
form
4
n
−
1
where
n
is
an
element
of
N
∗
.
Show
that
E
has
at
least
two
elements.
2
Assume
E
finite
.
Let
P
be
the
product
of
all
elements
of
E
and
X
=4
P
−
1
.
a
Find
a
minorant
of
X
.
b
Show
that
X
is
not
divisible
by
2
,
and
deduce
that
any
prime
factor
of
X
is
either
of
the
form
4
n
+1
,
or
of
the
form
4
n
−
1
where
n
is
an
element
of
N
∗
.
c
Show
that
X
has
at
least
one
prime
factor
of
the
form
4
n
−
1
where
n
is
an
element
of
N
∗
.
3
Considering
a
prime
factor
p
of
X
of
the
form
4
n
−
1
,
the
definition
of
P
and
the
relation
X
=4
P
−
1
,
complete
the
demonstration
by
the
absurd.
https://chingmath.fr
chapExoCorrec/336
sacados/336
chapExoCorrec/5302
sacados/5302