1 x 1! + 2 x 2 ! + 3 x 3! + ... + 13 x 13 !
Tìm số nguyên x, biết 13 ⋮ (2x + 3)
A. x ∈ {1; -1; 13; -13} B. x ∈ {1; 13}
C. x ∈ {-1; 5; -2; -8} D. x ∈ {1; 2; 5; 8}
Tìm x ∈ Z thỏa mãn; -1 < x < 2
A. x ∈ {0} B. x ∈ {-1;0;1;2} C. x ∈ {0;1} D. x ∈ {0;1;2}
Sắp xếp các số 0;-12; -4; 9; 234; -234 theo thứ tự giảm dần, chọn câu đúng?
A. 234; 0; 9; -4; -12; -234 B. -234; -4; 0; -12; 9; 234
C. -234; -12; -4; 0; 9; 234 D. 234; 9; 0; -4; -12; -234
1.(x+1)/35 + (x+3)/33 = (x+5)/33 + (x+7)/20
2. (X+1)/12+ (X+2)/13 = (X+3)/14+ (X+4)/15
3. (X-85)/15+ (X-75)/13+(X-67)/11+ (X-64)/9=10
4. (X-1)/13-(2X-13)/15=(3X-15)/27- (4X-27)/29
2: \(\Leftrightarrow\left(\dfrac{x+1}{12}-1\right)+\left(\dfrac{x+2}{13}-1\right)=\left(\dfrac{x+3}{14}-1\right)+\left(\dfrac{x+4}{15}-1\right)\)
=>x-11=0
=>x=11
3: \(\Leftrightarrow\left(\dfrac{x-85}{15}-1\right)+\left(\dfrac{x-74}{13}-2\right)+\left(\dfrac{x-67}{11}-3\right)+\left(\dfrac{x-64}{9}-4\right)=0\)
=>x-100=0
=>x=100
tìm x
a, 11/13 -( 5/42 - x) = - (15/28 - 11/13)
b, x +1/3 = 2/5-(-1/3)
c, 2/3 x +5/7 =3/10
d, 3/7-x = 1/4 - (-3/5)
e, -21/13 x + 1/3 = -2/3
11/13-(5/42-x)=(15/28-11/13)
11/13-(5/42-x)=-37/182
(5/42-x)=11/13+37/182
(5/42-x)=191/182
x=5/42-191/182
x=-254/273
vậy x=-254/273
bạn ấn vào chữ M nằm ngang ở dưới câu hỏi khi bạn trả lời là sẽ ấn được phân số nhé
còn gửi câu trả lời cũng tương tự
\(b,x+\frac{1}{3}=\frac{2}{5}-\left(-\frac{1}{3}\right)\)
\(< =>x+\frac{1}{3}=\frac{2}{5}+\frac{1}{3}\)
\(< =>x=\frac{1}{3}-\frac{1}{3}+\frac{2}{5}=\frac{2}{5}\)
\(c,\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)
\(< =>\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}=-\frac{29}{70}\)
\(< =>x=\frac{-29}{70}:\frac{2}{3}=-\frac{7}{140}\)
\(d,\frac{3}{7}-x=\frac{1}{4}-\left(-\frac{3}{5}\right)\)
\(< =>\frac{3}{7}-\frac{1}{4}-\frac{3}{5}=x\)
\(< =>x=-\frac{59}{140}\)
\(e,-\frac{21}{12}x+\frac{1}{3}=-\frac{2}{3}\)
\(< =>-\frac{21}{12}x=-\frac{2}{3}-\frac{1}{3}=-1\)
\(< =>x=\frac{12}{21}\)
tính nhanh : 3/5 x 7/9 + 11/9 x 3/5 - 3/10
14/13 : 1/2 + 3/13 x 2 - 2 x 7/13
sao ko quan tâm
Tìm số nguyên x ,nếu biết
a, \((\dfrac {1}{2}-\dfrac {1}{6}).3^x+3^{x+1}= 3^{16}+3^{13}\)
b, \((\dfrac {1}{2}-\dfrac {1}{3}).6^{x+2}-6^x = 6^{14}-6^{13}\)
c, \((\dfrac {1}{3}+\dfrac {1}{6}).2^{x+4}-2^x=2^{13}-2^{10}\)
d, \((\dfrac {1}{2}-\dfrac {1}{6}.3^{x+4} - 4.3^x =3^{16}-4.3^{13}\)
câu a) mình chịu (dùng kiến thức lớp 12 chắc làm đc haha)
b) gt ⇒ \(\frac{1}{6}.6^{x+2}-6^x=6^{14}-6^{13}\)
⇒ \(6^{x+1}-6^x=6^{14}-6^{13}\)
⇒ \(6^x\left(6-1\right)=6^{13}\left(6-1\right)\)
⇒ \(x=13\)
c) gt ⇒ \(\frac{1}{2}.2^{x+4}-2^x=2^{13}-2^{10}\)
⇒ \(2^{x+3}-2^x=2^{13}-2^{10}\)
⇒ \(2^x\left(2^3-1\right)=2^{10}\left(2^3-1\right)\)
⇒ \(x=10\)
d) gt ⇒ \(\frac{1}{3}.3^{x+4}-4.3^x=3^{16}-4.3^{13}\)
⇒ \(3^{x+3}-4.3^x=3^{16}-4.3^{13}\)
⇒ \(3^x\left(3^3-4\right)=3^{13}\left(3^3-4\right)\)
⇒ \(x=13\)
Hoàng Tử Hà
Y
Dương Bá Gia Bảo
Nguyễn Thị Diễm Quỳnh
lê thị hương giang
Vũ Huy Hoàng
Nguyễn Thị Linh Chi
Luân Đào
DƯƠNG PHAN KHÁNH DƯƠNG
Nguyễn Ngân Hòa
Nguyễn Huy Tú
Lightning Farron
m.n làm giúp mình với ak
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
`1, -2/9 xx 15/17 + (-2/9) xx 2/17`
`= -2/9 xx (15/17 + 2/17)`
`= -2/9 xx 17/17`
`=-2/9xx1`
`=-2/9`
__
`-5/3 xx 6/5 + (-7/9) xx 3/10`
`= -30/15 + (-21/90)`
`= -2 + (-7/30)`
`=-60/30 +(-7/30)`
`=-67/30`
__
`15/20 xx 7/5 + (-9/7) xx (-6/4)`
`=3/4 xx7/5 + (-9/7) xx(-6/4)`
`= 21/20 + 54/28`
`= 21/20 + 27/14`
`=417/140`
__
`-25/13 xx 5/19 + (-25/13) xx 14/19`
`=-25/13 xx (5/19 +14/19)`
`=-25/13 xx 19/19`
`= -25/13 xx 1`
`=-25/13`
__
`-7/13 xx 13/5 + (-9/7) xx 5/3`
`=-7/5 +(-15/7)`
`=-124/35`
1,Tìm x biết:
0,4:x=x:0,9
13/1/3:1/1/3=26:(2.x-1)
0,2:1/1/5=2/3:(6.x+7)
37-x/x+13=3/7
Bài 1: So sánh
1314-1313 với 1315-1314
Bài 2: Tìm x
3x+3x+1-3x+2+3x+3= 594
Bài 1:
ta có 1314<1315
1313<1314
=> dấu cân điền là"<"(1314 -1313 <1315-1314)
còn bài 2 thì sao bạn
Tính bằng cách thuận tiên nhất:
1):(3/4 x 5/97 + 1/9 x 13/47) x (1/5 - 7/25 x 5/7)
2): 8/17 x 4/15 + 8/17 x 22/15 - 8/15 x 9/17
3): 2021/2 x 1/3 + 4042/4 x 1/5 + 6063/3 x 22/15
4); 4/7 x 2/13 + 8/13 :7/4 + 4/7 : 13/2 + 4/7 x 1/13
5): 2022 x 2021 - 1/ 2021 + 2022 x 2020
6): 18 x 123 + 9 x 4567 x 2 + 3 x 5310 x 6 / (2 + 4 + 6 + 8 + ...+20 + 22) + 48
7): A= 2021 x 2021 x 202020 - 2020 x 2020 x 20212021 / 2020 x 20192019
1) Ta có: \(\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{7}{25}\cdot\dfrac{5}{7}\right)\)
\(=\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{1}{5}\right)\)
=0
2) Ta có: \(\dfrac{8}{17}\cdot\dfrac{4}{15}+\dfrac{8}{17}\cdot\dfrac{22}{15}-\dfrac{8}{15}\cdot\dfrac{9}{17}\)
\(=\dfrac{8}{17}\left(\dfrac{4}{15}+\dfrac{22}{15}-\dfrac{9}{15}\right)\)
\(=\dfrac{8}{17}\cdot\dfrac{15}{15}=\dfrac{8}{17}\)
3) Ta có: \(\dfrac{2021}{2}\cdot\dfrac{1}{3}+\dfrac{4042}{4}\cdot\dfrac{1}{5}+\dfrac{6063}{3}\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)+2021\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{8}{15}+\dfrac{2021}{2}\cdot\dfrac{44}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{52}{15}\)
\(=\dfrac{52546}{15}\)
4) Ta có: \(\dfrac{4}{7}\cdot\dfrac{2}{13}+\dfrac{8}{13}:\dfrac{7}{4}+\dfrac{4}{7}:\dfrac{13}{2}+\dfrac{4}{7}\cdot\dfrac{1}{13}\)
\(=\dfrac{4}{7}\left(\dfrac{2}{13}+\dfrac{8}{13}+\dfrac{2}{13}+\dfrac{1}{13}\right)\)
\(=\dfrac{4}{7}\)