Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
b,(723+277).2001-(456+544).1010-389-611
=1000.2001-1000.1010-(389+611)
=1000.2001-1000.1010-1000
=1000.(2001-1010-1)
=1000.990
=990000
a, 92.53+12.92-81+36.92
=92.(53+12+36)-81
=81.101-81
=8181-81
=8100
theo bai co 1/3+1/6+...+2/x.x+1=499/1000
(=)2/2.3+2/3.4+...+2/x.(x+1)=499/1000
(=)2(1/2-...-1/x+1)=499/1000
(=)1/2-1/x+1=499/2000
(=)1/x+1=501/2000
den day thi minh chiu roi!
\(x+x+x+x+x+x+x+x+999=456+572\)
\(\Rightarrow1x+1x+1x+1x+1x+1x+1x+1x+999=1028\)
\(\Rightarrow\left(1+1+1+1+1+1+1+1\right)x=1028-999\)
\(\Rightarrow8x=27\Rightarrow x=27\div8=\frac{27}{8}\)
x + x + x + x + x +x + x + x + 999 = 456 + 572
<=>(1 + 1 + 1 + 1 + 1+ 1 + 1 + 1).x + 999 = 1028
<=>8x + 999 = 1028
<=>8x = 1028 - 999
<=>8x = 29
<=>x=3.625
Thử lại
3,625 + 3,625 + 3,625 + 3,625 + 3,625 + 3,625 + 3,625 + 3,625 + 999 = 456 + 572
1028 = 1028
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) \(-x+821+534=499+\left(x-84\right)\)
\(\Leftrightarrow-x+821+534=499+x-84\)
\(\Leftrightarrow821+534-499+84=x+x\)
\(\Leftrightarrow940=2x\)
\(\Leftrightarrow x=\dfrac{940}{2}\)
\(\Leftrightarrow x=470\)
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 \(x=81\)
499 x 338 + 449 x 661 + 999 x 448
= 168662 + 329839 + 447552
= 498501 + 447552 = 946053
(728+277) x 2011 - (456+544) x 1010 - 389 -611
= 1005 x 2011 - 1000 x 1010 - 389 - 611
= 2021055 - 1010000 - 389 - 611
= 2021055 - ( 1010000 + 389 + 611 )
= 2021055 - 1011000
= 1010055
đúng thì like cho vs nha
thanks nhìu