Mn làm giúp mk vs ạ . Cảm ơn ạ ☺️😊😇

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part 1
1 which
2 won't
3 because
4 Good idea
5 on
6 therefore
part 2
1D 2F 3A 4B 5C 6E
part 3
1 studied
2 has worked
3 being interviewed
4 to be taken
5 would visit
6 put
7 endangered
8 compulsorily
part 4
1 are -> is
2 me -> to me
3 work -> working
4 when -> since
part 5
1 written novels for
2 to read bedtime stories
3 to wearing
4 has been absent from
5 doesn't have a passport
6 were given to Martha
7 play football that
8 whom my teacher was
part 6
1 mankind
2 polluted
3 of
4 naturally
part 7
1F 2F 3T 4T
1: \(2155-\left(174+2155\right)+\left(-68+174\right)\)
=2155-174-2155-68+174
=(2155-2155)+(174-174)-68
=-68
2: \(-25\cdot72+25\cdot21-49\cdot25\)
\(=25\left(-72+21-49\right)\)
\(=25\cdot\left(-100\right)=-2500\)
3: \(35\left(14-23\right)-23\left(14-35\right)\)
\(=35\cdot14-35\cdot23-23\cdot14+23\cdot35\)
\(=35\cdot14-23\cdot14=12\cdot14=168\)
4: \(8154-\left(674+8154\right)+\left(-98+674\right)\)
=8154-674-8154-98+674
=(8154-8154)+(674-674)-98
=0+0-98
=-98
5: \(-25\cdot21+25\cdot72+49\cdot25\)
\(=25\left(-21+72+49\right)\)
\(=25\cdot100=2500\)
6: \(27\left(13-16\right)-16\left(13-27\right)\)
\(=27\cdot13-27\cdot16-16\cdot13+16\cdot27\)
\(=27\cdot13-16\cdot13=11\cdot13=143\)
7: -1911-(1234-1911)
=-1911-1234+1911
=-1234
8: \(156\cdot72+28\cdot156\)
\(=156\cdot\left(72+28\right)\)
\(=156\cdot100=15600\)
9: \(32\cdot\left(-39\right)+16\cdot\left(-22\right)\)
\(=16\cdot\left(-78\right)+16\cdot\left(-22\right)\)
\(=16\cdot\left(-78-22\right)=16\cdot\left(-100\right)=-1600\)
10: -1945-(567-1945)
=-1945-567+1945
=-567
11: \(184\cdot33+67\cdot184\)
\(=184\cdot\left(33+67\right)\)
\(=184\cdot100=18400\)
12: \(44\cdot\left(-36\right)+22\cdot\left(-28\right)\)
\(=22\cdot\left(-72\right)+22\cdot\left(-28\right)\)
\(=22\cdot\left(-72-28\right)=22\cdot\left(-100\right)=-2200\)
a) Ta có: \(P=\dfrac{a\sqrt{a}-1}{a-\sqrt{a}}-\dfrac{a\sqrt{a}+1}{a+\sqrt{a}}+\left(\sqrt{a}-\dfrac{1}{\sqrt{a}}\right)\left(\dfrac{3\sqrt{a}}{\sqrt{a}-1}-\dfrac{\sqrt{a}+2}{\sqrt{a}+1}\right)\)
\(=\dfrac{\left(\sqrt{a}-1\right)\left(a+\sqrt{a}+1\right)}{\sqrt{a}\left(\sqrt{a}-1\right)}-\dfrac{\left(\sqrt{a}+1\right)\left(a-\sqrt{a}+1\right)}{\sqrt{a}\left(\sqrt{a}+1\right)}+\dfrac{a-1}{\sqrt{a}}\cdot\dfrac{3\sqrt{a}\left(\sqrt{a}+1\right)-\left(\sqrt{a}+2\right)\left(\sqrt{a}-1\right)}{\left(\sqrt{a}-1\right)\left(\sqrt{a}+1\right)}\)
\(=\dfrac{a+\sqrt{a}+1-a+\sqrt{a}-1}{\sqrt{a}}+\dfrac{3a+3\sqrt{a}-\left(a-\sqrt{a}+2\sqrt{a}-2\right)}{\sqrt{a}}\)
\(=2+\dfrac{3a+3\sqrt{a}-a+\sqrt{a}-2\sqrt{a}+2}{\sqrt{a}}\)
\(=\dfrac{2\sqrt{a}+2a+2\sqrt{a}+2}{\sqrt{a}}\)
\(=\dfrac{2\left(a+2\sqrt{a}+1\right)}{\sqrt{a}}\)
\(=\dfrac{2\left(\sqrt{a}+1\right)^2}{\sqrt{a}}\)
b) Ta có: \(P-6=\dfrac{2\left(\sqrt{a}+1\right)^2-6\sqrt{a}}{\sqrt{a}}\)
\(=\dfrac{2a+4\sqrt{a}+2-6\sqrt{a}}{\sqrt{a}}\)
\(=\dfrac{2\left(a-\sqrt{a}+1\right)}{\sqrt{a}}>0\forall a\) thỏa mãn ĐKXĐ
hay P>6
Bài 1:
A\(\cap\) B=(-3;4]\(\cap\) (2;6)
=(2;4]
A\(\cup\) B=(-3;4]\(\cup\) (2;6)
=(-3;6)
A\B=(-3;4]\(2;6)
=(-3;2]
Bài 2:
a: \(\left(x+2\right)\left(2x^2-3x-2\right)=0\)
=>\(\left(x+2\right)\left(2x^2-4x+x-2\right)=0\)
=>(x+2)(x-2)(2x+1)=0
=>x∈{-2;2;-1/2}
mà x∈Z
nên x∈{2;-2}
=>A={2;-2}
b: -2<=n<=2
mà n là số nguyên
nên n∈{-2;-1;0;1;2}
=>(n+1)∈{-1;0;1;2;3}
=>n(n+1)∈{2;-1;0;2;6}
=>B={-1;0;2;6}
Phần bù của A trong B là \(C_{B}A\) =B\A={-1;0;2;6}\{2;-2}
={-1;0;6}
a)
Thể tích vật: V1 = 0,3.0,2.0,15 = 9.10-3m3
Thể tích vật khi rỗng: V2 = 0,15.0,1.0,25 = 3,75.10-3m3
Thể tích thủy tinh:
V = V1 - V2 = 9.10-3 - 3,75.10-3 = 5,25.10-3 = 0,00525m3
Trọng lượng vật: P = 14000.0,00525 = 73,5 N
Do vật nổi => F = P = 73,5N
Chiều cao phần chìm trong nước của thủy tinh:
h = \(\dfrac{F_A}{d.s}=\dfrac{73,5}{10000.0,3.0,2}=0,1225m=12,25cm\)
Chiều cao phần nổi: h' = 15 - 12,25 = 2,75cm
b) Bắt đầu chìm:
FA' = d.V1 = 10000.0,3.0,2.0,15 = 90N
=> P' = FA' = 90N
Trọng lượng nước rót vào: P1 = P' - P = 90 - 73,5 = 16,5N
Chiều cao cột nước rót vào:
\(h''=\dfrac{P_1}{d.0,25.0,15}=\dfrac{16,5}{10000.0,25.0,15}=0,044m=4,4cm\)
Cảm ơn bạn nhiều ☺️