1, 7+x-(5+2x)>31-6
2, 15-x-(41-2x)<16-23
giải hộ mình,nhanh nhé!
Những câu hỏi liên quan
(x-1)x+2=(x-1)x+4
1/ 4 . 2/6 . 3/8 . 4/10 . 5/15 .... 30/62 . 31/64= 2x
a) Ta có: \(\left(x-1\right)^{x+2}-\left(x-1\right)^{x+4}=0\)
\(\Leftrightarrow\left(x-1\right)^x\cdot\left(x-1\right)^2-\left(x-1\right)^x\cdot\left(x-1\right)^4=0\)
\(\Leftrightarrow\left(x-1\right)^{x+2}\cdot\left[1-\left(x-1\right)^2\right]=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x-1=1\\x-1=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=2\\x=0\end{matrix}\right.\)
b) Ta có: \(\dfrac{1}{4}\cdot\dfrac{2}{6}\cdot\dfrac{3}{8}\cdot\dfrac{4}{10}\cdot\dfrac{5}{15}\cdot...\cdot\dfrac{30}{62}\cdot\dfrac{31}{64}=2x\)
\(\Leftrightarrow2x=\dfrac{1}{64}\)
hay \(x=\dfrac{1}{128}\)
Đúng 0
Bình luận (0)
(25.21 + 25.51) : 36
{188 - [ 33 + (62 - 7.3)]}:70
tìm x
(x - 1)(15-3x)=0
720: [ 41-(2x + 5)]=23.5
\(\left(25\cdot21+25\cdot51\right):36\\ =\left[25\cdot\left(21+51\right)\right]:36\\ =\left(25\cdot72\right):36\\ =1800:36\\ =50\\ \left\{188-\left[33+\left(6^2-7\cdot3\right)\right]\right\}:70\\ =\left\{188-\left[33+\left(36-21\right)\right]\right\}:70\\ =\left[188-\left(33+15\right)\right]:70\\ =\left(188-48\right):70\\ =140:70\\ =2\)
\(\left(x-1\right)\left(15-3x\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-1=0\\15-3x=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=1\\3x=15\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=5\end{matrix}\right.\)
\(720:\left[41-\left(2x+5\right)\right]=2^3\cdot5=8\cdot5\\ \Rightarrow720:\left[41-\left(2x+5\right)\right]=40\\ \Rightarrow41-\left(2x+5\right)=720:40\\ \Rightarrow41-\left(2x+5\right)=18\\ \Rightarrow2x+5=41-18\\ \Rightarrow2x+5=23\\ \Rightarrow2x=23-5\\ \Rightarrow2x=18\\ \Rightarrow x=18:2\\ \Rightarrow x=9\)
Đúng 0
Bình luận (0)
a) (25.21 + 25.51) : 36
= [ 25.( 21 + 51 ) ] : 36
= [ 25. 72 ] : 36
= 1800 : 36
= 50.
Đúng 0
Bình luận (0)
(2x-4).(3-x) 720 : [ 41-(2x-5)]=22.5 15-x=7-(-2)
720 : [41-(2x-5)]=22.5 15-x=7- (-2) [230- (15-5x)].3=390
720 : [ 41 - (2\(x\) - 5)] = 22.5
41 - (2\(x\) - 5) = 720 :110
2\(x\) - 5 = 41 - \(\dfrac{72}{11}\)
2\(x\) - 5 = \(\dfrac{379}{11}\)
2\(x\) = \(\dfrac{379}{11}\) + 5
2\(x\) = \(\dfrac{434}{11}\)
\(x\) = \(\dfrac{434}{11}\) : 2
\(x\) = \(\dfrac{217}{11}\)
Đúng 0
Bình luận (0)
15 - \(x\) = 7 - (-2)
15 - \(x\) = 7 + 2
15 - \(x\) = 9
\(x\) = 15 - 9
\(x\) = 6
Đúng 0
Bình luận (0)
[230 - (15 - 5\(x\))]. 3 = 390
230 - (15 - 5\(x\)) = 390 : 3
230 - 15 + 5\(x\) = 130
215 + 5\(x\) = 130
5\(x\) = 215 - 130
5\(x\) = -85
\(x\) = -85 : 5
\(x\) = - 17
Đúng 0
Bình luận (0)
Tìm x:
a,(15-x)+(x-12) = 7-(-8+x)
b,3.(x+2) - 6.(x-5) = 2.(5-2x)
c,(-12+x) - (2x+31) = (-6)-5
d,-2.(2x-8)+3.(4-2x) = -72-5.(3x-7)
e,2x+1 chia hết x-3
g,-2x-11 chia hết 3x+2
Các bạn làm giúp mình nha! Thanks!!!! ^_^ :D :)))
Tìm x, biết:
a) x-20 =-2x +37
b)4(x-5)-31=(-6)-(x+1)
c)-8(x+3)-x=10-(2x-5)
d)15-4(x+7)=-6+(x-10)
Tính :
23/31 x 5/46 - 3/62
4/15 x 7/16 x 5/4
23/31 χ 5/46 - 3/62 = 5/62 - 3/62 = 1/31 ; 4/15 χ 7/16 χ 5/4 = 7/60 χ 5/4 = 7/48
Đúng 0
Bình luận (0)
Bài 27. Tìm x biết
a. 89 – (73 – x) 20 b. (x + 7) – 25 13 c. 98 – (x + 4) 20
d. 140 : (x – 8) 7 e. 4(x + 41) 400 f. x – [ 42 + (–28)] –8
g. x + 5 20 – (12 – 7) h. (x – 11) 2.2³ + 20 : 5 i. 4(x – 3) 7² – 1³.
j. 2x+1.22014 22015. k. 2x – 49 5.3² ℓ. 3²(x + 14) – 5² 5.2²
m. 6x + x 511 : 59 + 31. n. 7x – x 521 : 519 + 3.2² – 70.
o. 7x – 2x 617 : 615 + 44 : 11. p. 3x 9 q. 4x 64
r. 9x–1 9 s. x4 16 t. 2x : 25 1
u. |x – 2| 0 v. |x – 5| 7 – (–3) w. |x – 5| |–7|
x. |x| – 5 3 y. 15 –...
Đọc tiếp
Bài 27. Tìm x biết
a. 89 – (73 – x) = 20 b. (x + 7) – 25 = 13 c. 98 – (x + 4) = 20
d. 140 : (x – 8) = 7 e. 4(x + 41) = 400 f. x – [ 42 + (–28)] = –8
g. x + 5 = 20 – (12 – 7) h. (x – 11) = 2.2³ + 20 : 5 i. 4(x – 3) = 7² – 1³.
j. 2x+1.22014 = 22015. k. 2x – 49 = 5.3² ℓ. 3²(x + 14) – 5² = 5.2²
m. 6x + x = 511 : 59 + 31. n. 7x – x = 521 : 519 + 3.2² – 70.
o. 7x – 2x = 617 : 615 + 44 : 11. p. 3x = 9 q. 4x = 64
r. 9x–1 = 9 s. x4 = 16 t. 2x : 25 = 1
u. |x – 2| = 0 v. |x – 5| = 7 – (–3) w. |x – 5| = |–7|
x. |x| – 5 = 3 y. 15 – 2|x| = 13
a) 89-(73-x) = 20
=> 73+x =89-20
=> 73+x=69
=> x=69-73
=> x=-4
b) (x+7)-25=13
=> x+7=13+25
=> x+7=38
=> x=38-7
=> x=31
c) 98-(x+4)=20
=> x+4=98-20
=> x+4=78
=> x=78-4
=> x=73
Đúng 1
Bình luận (0)
d) 140:(x-8)=7
=> x-8=140:7
=> x-8=20
=> x=20+8
=> x=28
e) 4(x+41)=400
=> x+41=400:4
=> x+41=100
=> x=100-41
=> x=59
f) x-[42+(-28)]=-8
=> x-14=-8
=> x=-8+14
=> x=6
Đúng 1
Bình luận (0)
g) x+5=20-(12-7)
=> x+5=20-5
=> x+5=15
=> x=15-5
=> x=10
h) \(x-11=2.2^3+20:5\)
=> x-11=2.8+4
=> x-11=16+4
=> x-11=20
=> x=20+11
=> x=31
i) \(4\left(x-3\right)=7^2-1^3\)
=> 4(x-3)=49-1
=> 4(x-3)=48
=> x-3=48:4
=> x-3=12
=> x=12+3
=> x=15
Đúng 0
Bình luận (0)
Xem thêm câu trả lời
Tìm x biết
a, x(5-3,5x)+3,5x(x-1)=15
b,0,6x(x-50)-0,3x(2x-80)=0,12
c,(6x-4)(2x-7)+(3x-5).(1-4x)=-31
GIÚP MK VS MK ĐG CẦN GẤP