Hãy tính:
-32 + { -54: [(-2)3 + 7 . |-2| ]. (-2)2
giúp mk nhé
Thanks
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A = -32 + { -54: [(-2)8 + 7].(-2)2 }
A = -9 + { -54 : [ 256 + 7].4 }
A = - 9 + { -54 : 263.4}
A = -9 - \(\dfrac{216}{263}\)
A = - \(\dfrac{2583}{263}\)
a: \(=\dfrac{x-2x-1}{x+1}=\dfrac{-\left(x+1\right)}{x+1}=-1\)
b: \(=\dfrac{2+2x}{x\left(x+1\right)}=\dfrac{2\left(x+1\right)}{x\left(x+1\right)}=\dfrac{2}{x}\)
c: \(=\dfrac{3x-1}{2\left(3x+1\right)}+\dfrac{3x+1}{2\left(3x-1\right)}-\dfrac{6x}{\left(3x-1\right)\left(3x+1\right)}\)
\(=\dfrac{9x^2-6x+1+9x^2+6x+1-12x}{2\left(3x-1\right)\left(3x+1\right)}=\dfrac{18x^2-12x+2}{2\left(3x-1\right)\left(3x+1\right)}\)
\(=\dfrac{2\left(3x-1\right)^2}{2\left(3x-1\right)\left(3x+1\right)}=\dfrac{3x-1}{3x+1}\)
CTHH | Phân loại | Gọi tên |
H2SO3 | Axit | axit sunfurơ |
H2S | Axit | axit sunfuhiđric |
FeS | Muối | Sắt (II) sunfit |
Fe(OH)3 | Bazo | Sắt (III) hiđroxit |
Fe3O4 | Oxit | Sắt từ oxit |
HNO3 | Axit | axit nitric |
Cu(OH)2 | Bazo | Đồng (II) hiđroxit |
SO3 | Oxit | Lưu huỳnh trioxit |
Ca(HCO3)2 | Muối | Canxi hiđrocacbonat |
Oxit bazo:
\(Fe_3O_4\) sắt từ oxi.
Oxit axit:
\(SO_3\) lưu huỳnh trioxit.
Bazo:
\(Fe\left(OH\right)_3\) sắt(lll) hidroxit
\(Cu\left(OH\right)_2\) đồng(ll) hidroxit
Axit:
\(H_2SO_3\) axit sunfuro
\(H_2S\) hidrosunfide
\(HNO_3\) axit nitric
Muối:
\(FeS\) sắt(ll) sunfide
\(Ca\left(HCO_3\right)_2\) canxi hidrocacbonat
\(B=7^5:7^3-6^2\cdot2+2^3\cdot2^2\)
\(B=7^2-36\cdot2+2^5\)
\(B=49-36\cdot2+32\)
\(B=49-72+32\)
\(B=9\)
\(a)245^2+490\cdot54+54^2-199^2\\=(245^2+2\cdot245\cdot54+54^2)-199^2\\=(245+54)^2-199^2\\=299^2-199^2\\=(299-199)(299+199)\\=100\cdot498\\=49800\\---\\b)356^2-356\cdot246+123^2-133^2\\=(356^2-2\cdot356\cdot123+123^2)-133^2\\=(356-123)^2-133^2\\=233^2-133^2\\=(233-133)(233+133)\\=100\cdot366\\=36600\)
\(---\)
\(c)468^2-412^2-110\cdot412-55^2\\=468^2-(412^2+110\cdot412+55^2)\\=468^2-(412^2+2\cdot412\cdot55+55^2)\\=468^2-(412+55)^2\\=468^2-467^2\\=(468-467)(468+467)\\=1\cdot935\\=935\\---\)
\(d)615^2+250\cdot615+125^2-540^2\\=(615^2+2\cdot615\cdot125+125^2)-540^2\\=(615+125)^2-540^2\\=740^2-540^2\\=(740-540)(740+540)\\=200\cdot1280\\=256000\)
#\(Toru\)
a) \(29.31=\left(30-1\right)\left(30+1\right)=30^2-1=900-1=899\)
b) \(33,3^2-2.33,3.3,3+3,3^2=\left(33,3-3,3\right)^2=30^2=900\)
c) \(20,1.19,9=\left(20+0,1\right)\left(20-0,1\right)=20^2-0,1^2=400-0.01=399,99\)
d) \(37^2+2.37.13+13^2=\left(37+13\right)^2=50^2=2500\)
1: =>x=-5/3-1/2=-13/6
2: =>x=1/3-3/5=-4/15
4: =>x=-7/9+4/3=-7/9+12/9=5/9
5: =>x=5/6-7/3=5/6-14/6=-9/6=-3/2
6: =>x=9/10+1/5=11/10
7: =>x=3/8-5/12=36/96-40/96=-1/24
8: Đề sai rồi bạn
(1 + 2 + 3 + ... + 31 + 32) : 11 + 2
= [(32 + 1).(32 - 1 + 1) : 2] : 11 + 2
= (33 . 32 : 2) : 11 + 2
= 33 . 16 : 11 + 2
= 3 . 16 + 2
= 48 + 2
= 50
\(-3^2+\left\{-54:\left[\left(-2\right)^3+7.|-2|\right]\right\}.\left(-2\right)^2\)'
=\(9+\left\{-54:\left[\left(-8\right)+7.2\right]\right\}.4\)
\(=9+\left\{-54:\left[\left(-8\right)+14\right]\right\}.4\)
\(=9+\left\{-54:6\right\}.4\)
\(=9+\left(-9\right).4\)
\(=9+\left(-36\right)\)
\(=-27\)
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