Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) \(-x+821+534=499+\left(x-84\right)\)
\(-x-x=499-84-821-534\)
\(-2x=-940\)
\(x=470\)
b) \(x-96=\left(448-x\right)-150\)
\(x+x=448-150+96\)
\(2x=394\)
\(x=197\)
c) \(-\left(754+x\right)=\left(x-12-741\right)-23\)
\(-754-x=x-12-741-23\)
\(-x+x=-12-741-23+754\)
\(0x=2\)
\(x\)ko tồn tại
d) \(\left(6+x\right)-\left(17-21\right)=-25\)
\(6+x-17+21=-25\)
\(x=-25-6+17-21\)
\(x=-35\)
e) \(17-\left(x+2\right)=3\)
\(17-x-2=3\)
\(-x=3-17+2\)
\(-x=-12\)
\(x=12\)
h) \(-10-\left(31-x\right)=40\)
\(-10-31+x=40\)
\(x=40+10+31\)
\(x=81\)
k mk nha bạn 
a) (-30) + 17 + (-70) + 33
=[-30+(-70)]+(17+33)
=-100+50
=-50
b) 56 - 15 - 6 + (-75)
=(56-6)-[15+(-75)]
=50-(-60)
=110
c) (157 - 56) - (44 + 57)
=157-56-44+57
=(-157-57)-(56+44)
=-100-100
=-200
d) (-24 + 174) - (174 - 24)
=-24+174-174+24
=(-24+24)+(174-174)
=0+0
=0
e) (35 - 47) - (-123 + 35) + [20 - (123 - 57)]
=35-47+123-35+[20-123+57]
=35-47+123-35+20-123+57
=(35-35)+(123-123)+(-47+57)
=0+0+(-10)
=-10
a) 11-12+13-14+15-16+17-18+19-20
= -1 + ( -1 )+ ( -1 )+ ( -1 )+ ( -1 )
= -1 . 5
= -5
b) 101-102-(-103)-104-(105)-106-(107)-108-(-109)-110
= -1 + ( -1 )+ ( -1 )+ ( -1 )+ ( -1 )
= -1 . 5
= -5
Câu 1 : Thực hiện phép tính.
a. 17.64 + 17.36 + 315
= 17 . ( 64 + 36 ) + 315
= 17 . 100 + 315
= 1700 + 315
= 2015
b. 25 + [(-38) + (-25)] + 18
= 25 + ( -38) + (-25) + 18
= [ 25 + (-25) ] + [ (-38) + 18 ]
= 0 + (-20)
= -20
.
a) \(-x+821+534=499+\left(x-84\right)\)
\(\Leftrightarrow-x+821+534=499+x-84\)
\(\Leftrightarrow821+534-499+84=x+x\)
\(\Leftrightarrow940=2x\)
\(\Leftrightarrow x=\dfrac{940}{2}\)
\(\Leftrightarrow x=470\)
Vậy \(x=470\)
b) \(x-96=\left(448-x\right)-150\)
\(\Leftrightarrow x-96=448-x-150\)
\(\Leftrightarrow x+x=96+448-150\)
\(\Leftrightarrow2x=394\)
\(\Leftrightarrow x=\dfrac{394}{2}\)
\(\Leftrightarrow x=197\)
Vậy \(x=197\)
c) \(- (754 + x) = (x - 12 - 741) - 23\)
\(\Leftrightarrow-754-x=x-12-741-23\)
\(\Leftrightarrow-754+12+741+23=x+x\)
\(\Leftrightarrow22=2x\)
\(\Leftrightarrow x=\dfrac{22}{2}\)
\(\Leftrightarrow x=11\)
Vậy \(x=11\)
d) \((6 + x) - (17 - 21) = -25\)
\(\Leftrightarrow6+x-17+21=-25\)
\(\Leftrightarrow x=-25-6+17-21\)
\(\Leftrightarrow x=-35\)
Vậy \(x=-35\)
e) \(17-\left(x+2\right)=3\)
\(\Leftrightarrow17-x-2=3\)
\(\Leftrightarrow17-2-3=x\)
\(\Leftrightarrow x=12\)
Vậy \(x=12\)
h) \(-10 - (31 - x) = 40\)
\(\Leftrightarrow-10-31+x=40\)
\(\Leftrightarrow x=40+10+31\)
\(\Leftrightarrow x=81\)
Vậy \(x=81\)
\(a,0,5x-\frac{2}{3}x=\frac{7}{12}\Rightarrow\frac{1}{2}x-\frac{2}{3}x=\frac{7}{12}\)
\(\Rightarrow x\left(\frac{1}{2}-\frac{2}{3}\right)=\frac{7}{12}\Rightarrow x\cdot\left(\frac{3}{6}-\frac{4}{6}\right)=\frac{7}{12}\)
\(\Rightarrow x\cdot\left(-1\right)=\frac{7}{12}\Rightarrow x=\frac{7}{12}:\left(-1\right)=\frac{7}{-12}\)
\(c,\frac{\left(x-5\right)}{12}\cdot\frac{9}{29}=\frac{-6}{29}\Rightarrow\frac{\left(x-5\right)}{12}=\frac{-6}{29}:\frac{9}{26}\)
\(\frac{\Rightarrow\left(x-5\right)}{12}=\frac{-6}{9}=\frac{-2}{3}\Rightarrow x-5=-\frac{2}{3}\cdot12\)
\(\Rightarrow x-5=\frac{-24}{3}=-8\Rightarrow x=-8+5=-3\)
\(a,0,5x-\frac{2}{3}x=\frac{7}{12}\)
\(\Rightarrow\frac{1}{2}x-\frac{2}{3}x=\frac{7}{12}\)
\(\Rightarrow-\frac{1}{6}x=\frac{7}{12}\)
\(\Rightarrow x=-\frac{7}{2}\)
\(c,\frac{x-5}{12}\cdot\frac{9}{29}=-\frac{6}{29}\)
\(\Rightarrow\frac{x-5}{12}=-\frac{2}{3}\)
\(\Rightarrow x-5=12.\left(-\frac{2}{3}\right)\)
\(\Rightarrow x-5=-8\)
\(\Rightarrow x=-3\)
a) x + 118 = 218
x = 218 – 118
x = 100
b) 18 – x = -17
X = 18 – (-17)
X = 35
c) (-18) – x = -17
X = (-18) – (-17)
X = -1
d)124 + (118 – x) = 217
118 – x = 93
X = 118 – 93
X = 25
e) (3x – 6).3 = 34
(3x – 6).3 = 81
3x – 6 = 27
3x = 33
ð X = 11
g) 23.(42 – x) = 46
42 – x = 2
ð X = 40
h) 84 – (3x + 8) = 34
3x + 8 = 84 – 34
3x + 8 = 50
3x = 50 – 8
3x = 42
X = 42 : 3
ð X = 14
i) 3.(2x + 1) – 19 = 14
3.(2x + 1) = 14 + 19
3.(2x + 1) = 33
2x + 1 = 33 : 3
2x + 1 = 11
2x = 11 – 1
2x = 10
X = 10 : 2
ð X = 5
k) 6x – 302 = 23.5
6x – 302 = 40
6x = 40 + 302
6x = 342
X = 342 : 6
ð X = 57
m) (x – 1)2 = 81
(x – 1)2 = 92
ð X – 1 = 9
ð X = 9 + 1
ð X = 10
n) 2x+1 – 5 = 27
2x+1 = 27 + 5
2x+1 = 32
2x+1 = 25
ð X = 4
Chọn B