Giúp mik bài 4 nhanh vs ạk, cảm ơn ae nhìu😁
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Bài 5:
a) \(x^2-xy+x-y\)
\(=\left(x^2-xy\right)+\left(x-y\right)\)
\(=x\left(x-y\right)+\left(x-y\right)\)
\(=\left(x+1\right)\left(x-y\right)\)
b) \(xz+yz+4x+4y\)
\(=\left(xz+yz\right)+\left(4x+4y\right)\)
\(=z\left(x+y\right)+4\left(x+y\right)\)
\(=\left(z+4\right)\left(x+y\right)\)
c) \(x^2-x-y^2+y\)
\(=\left(x^2-y^2\right)-\left(x-y\right)\)
\(=\left(x+y\right)\left(x-y\right)-\left(x-y\right)\)
\(=\left(x-y\right)\left(x+y-1\right)\)
d) \(x^2+2x+2z-z^2\)
\(=\left(x^2-z^2\right)+\left(2x+2z\right)\)
\(=\left(x+z\right)\left(x-z\right)+2\left(x+z\right)\)
\(=\left(x+z\right)\left(x-z+2\right)\)
C5:
nC2H5OH = 8,2 / 46 = 0,2 (mol)
C2H5OH + 3O2-- (t^o)-- > 2CO2 + 3H2O
VCO2 = 0,4 . 22,4 = 8,96 (l)
VO2 = 0,6.22,4=13,44 (l)
28 I haven't gone to HCM City for 2 years
29 We have lived in My Tho for ten years
30 Lan didn't go to school last week
31 He was at home yesterday
Question8:
29. We live in Phu Tho about ten years.
30. I will see him tomorrow.
31. Lan didn't go to school last week
32. He was at home yesterday.
4P+5O2-to>2P2O5
0,2-------0,08 mol
n P=\(\dfrac{6,4}{31}\)=\(\dfrac{32}{155}\) mol
n O2=\(\dfrac{4,48}{22,4}=0,2mol\)
=>P dư
m P dư =\(\dfrac{9}{775}\).31=0,36g
=>m P2O5= 0,08.142=11,36g