Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
nếu ta xóa đi chữ số hàng chục và hàng đơn vị của số đó đi thì số đó giảm đi 100 lần và giá trị của số hàng chục và hàng đơn vị ghép lại
Vậy giá trị đó là : 1983 : (100 - 1 ) = 20 dư 3
Vậy giá trị của số hàng chục và hàng đơn vị ghép lại là 03
Số đó là : (1983 - 3 ) : 99 x 100 + 3 =2003
Đáp số : 2003
Bài 1
a0b = ab x 7
a x 100 + b = ( a x 10 + b ) x7
a x 100 + b = a x 10 x 7 + b x 7
Cùng bớt đi b
a x 100 = a x 70 + b x 6
Cùng bớt đi a x 70
a x 30 = b x 6
Cùng chia cho 6
a x 5 = b x 1
=>a = 1 ; b = 5
Vậy số đó là 15
2 bài kia bạn tự giải nha , mk lười lắm :)))))
cau hoi nay la cau hoi co 3 chu so chu khong hai la 2chu so
Gọi số có 4 chữ số cần tìm là \(\overline{abcd}\)
Theo đề ra, ta có: Khi xóa đi chữ số hàng chục và hàng đơn vị ta được số \(\overline{ab}\)
\(\overline{abcd}-\overline{ab}=3663\)
\(\overline{ab}\times100+\overline{cd}-\overline{ab}=3663\)
\(\overline{ab}\times99+\overline{cd}=3663\)
\(\overline{cd}=99\times\left(37-\overline{ab}\right)\)
Mà tích của 99 là một số tự nhiên bé hơn 100 nên có hai trường hợp là \(37-\overline{ab}=0\) hoặc \(37-\overline{ab}=1\)
Trường hợp 1: \(37-\overline{ab}=0\Rightarrow\overline{ab}=37\)
\(\Rightarrow\overline{cd}=0\)
Trường hợp 2: \(37-\overline{ab}=1\Rightarrow\overline{ab}=36\)
\(\Rightarrow\overline{cd}=99\)
Vậy số tự nhiên có 4 chữ số cần tìm là \(3700;3699\).
Gọi số cần tìm là \(\overline{abcd}\)
Xóa đi chữ số hàng chục và hàng đơn vị ta được số ab
Theo bài ra ta có:
\(\overline{abcd}-\overline{ab}=3663\)
\(100.ab+cd-ab=3663\)
\(cd+100.ab-ab=3663\)
\(cd+99.ab=3663\)
\(\Rightarrow cd=99.\left(37-ab\right)\)
\(\Rightarrow37-ab=0\) hoặc \(37-ab=1\)
Nếu 37 - ab = 0 thì ab = 37 và cd = 00
Nếu 37 - ab = 1 thì ab=36 và cd = 99
Vậy số cần tìm là: 3700 và 3699
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gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg
fd
fg
g
g
g
g
g
g
g
g
g
g
g
g
g
yh
u
yt
tu
yt
eawr
we
r
tt
ryh
fyu
gfykhj
k
j
lhj
gi8
et
e
rsdth
dfyg
hndf
jfh
frghy
fg
h
f
j
fh
f
g
d
gf
h
fh
dhfg
dfhf
tr;dg
dg
g
fh
g
hg
g
gh
gg
h
hg
hg
h
t
t
t
t
t
sd
d
xdf
ghf
j
ghu
i
tfr
cxf
j
udse5ytr
77es
5
65
6
t
frf
g
c
g
tr
yt
f
v
g
v
tf
,
tfv
j
f
b
t
b
hy
n
gh
g
g
g
g
gf
41
4
4
2
42
24
24
24
24
24
2
5
2
24
44
2
45
452
2
12
2
2
22
4
1
24
4
4
5
42
4
14
2
42
24
25
4
4
44
5
tyhyf
tghy
f
h
fgh
dg
hg
fj
gh
k
jj
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
j
gọi số ban đầu có dạng : \(\overline{abcd}\)
ta có : \(\overline{abcd}-\overline{ab}=3663\Leftrightarrow99\overline{ab}+\overline{cd}=3663\)'mà :
\(99\overline{ab}\le99\overline{ab}+\overline{cd}\le99\overline{ab}+99\)
Vậy : \(99\overline{ab}\le3663\le99\overline{ab}+99\) hay : \(36\le\text{}\overline{ab}\le37\)
vậy \(\orbr{\begin{cases}ab=36\Rightarrow3699\\ab=37\Rightarrow3700\end{cases}}\)
Vậy ta có hai số thỏa mãn đề bài là 3699 và 3700
Gọi số đó là abcd, ta có :
abcd - ab = 3663
ab * 100 + cd - ab = 3663
ab * ( 100 - 1 ) + cd = 3663
ab * 99 + cd = 3663
Thử lại : 3663 : 99 = 27
Số cần tìm là 2700
Gọi số cần tìm có dạng là \(X=\overline{abcd}\)
Khi xóa đi chữ số hàng chục và hàng đơn vị của một số tự nhiên thì số đó giảm đi 3663 đơn vị nên ta có:
\(\overline{abcd}-\overline{ab}=3663\)
=>\(1000a+100b+10c+d-10a-b=3663\)
=>\(990a+99b+10c+d=3663\)
=>(a,b,c,d)=(3;6;9;9); (a,b,c,d)=(3;7;0;0)
Vậy: Hai số cần tìm là 3699 và 3700
1,
gọi ab là số cần tìm (a khác 0)
gọi a0b là số ab sau khi thêm 0 vào chính giữa
gọi 1a0b là số a0b sau khi thêm 1 vào bên trái
ta có:
ab x 10=a0b
(ax10+bx1)x10=a0b
ax100+bx10=ax100+bx1
bx10=b(cùng trừ 2 vế cho a*100)
vì b x10=b nên b chỉ có thể là 0
vì b=0 nên ab=a0 và a0b=a00
ta lại có : a00x 3=1a00
a00 x 3=1000+a00
a00 x 2=1000(cùng trừ hai vế cho a00)
a00=1000:2
a=5
Vậy ab = 50
Gọi số cần tìm là abcd. Xóa đi chữ số hàng chục và đơn vị ta được số ab
Ta có :
abcd - ab = 3663
ab x100 + cd -ab = 3663
cd + ab x100 - ab = 3663
cd + ab x 99 = 3663
cd = 3663 - ab x99
cd = 37 x 99 - ab x 99
cd = (37- ab) x 99
Nhận xét : Tích của 99 với 1 số tự nhiên là một số bé hơn 100 nên 37 - ab phải = 0 hoặc1
Nếu 37 - ab = 0 thì ab = 37 và cd = 00
Nếu 37 - ab = 1 thì ab = 36 và cd = 99
Vậy số cần tìm là 3700 hoặc 3699
3700 hoac 3699 ban a