1. I wish they came here on time

2.I wish it didn't rain heavily

3.I wish she would go to Ha Noi with me tommorow

4.I wish Tom could help me

5.I wish my sister was here

6.I wish he went to school time

7.I wish he didn't fail the final examination

8.I wish I mustn't go now

9.I wish she wouldn't sell her house next week

10.I wish Mary was stay at home on sunday

a)ĐKXĐ:x\(\ne\)2;-2

b)A=\(\left[\dfrac{x+2}{2\left(x-2\right)}-\dfrac{2-x}{2\left(x+2\right)}+\dfrac{8}{\left(x-2\right)\left(x+2\right)}\right].\dfrac{x-2}{x-1}\)

A=\(\dfrac{\left(x+2\right)^2-\left(2-x\right)^2+16}{2\left(x-2\right)\left(x+2\right)}.\dfrac{x-2}{x-1}\)

A=\(\dfrac{8x+16}{2\left(x+2\right)}.\dfrac{1}{x-1}\)=\(\dfrac{8\left(x+2\right)}{2\left(x+2\right)}.\dfrac{1}{x-1}\)

A=\(\dfrac{4}{x-1}\)

c) Để A=1\(\Rightarrow\dfrac{4}{x-1}=1\)

\(\Rightarrow4=x-1\)\(\Rightarrow x=5\)

a)ĐKXĐ:\(x\ge0,x\ne4\)

b)M=\(\dfrac{\sqrt{x}\left(\sqrt{x}+2\right)+\sqrt{x}\left(\sqrt{x}-2\right)}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-2\right)}.\dfrac{x-4}{\sqrt{4x}}\)

M=\(\dfrac{2x}{x-4}.\dfrac{x-4}{\sqrt{4x}}\)=\(\sqrt{x}\)

c) để M>3\(\Rightarrow\)\(\sqrt{x}>3\)\(\Rightarrow x>9\)

BBDCCDACBA

1. If Laura had enough money, she would buy the shirt

2.the snow prevented the train from running

3.tom has less book than jack

4.she is both beautiful and intelligent

2b)

xét vế trái ta có

=\(\left(\sqrt{x}-\sqrt{y}\right).\dfrac{\sqrt{x^2y}+\sqrt{xy^2}}{\sqrt{xy}}\) \(\left(\sqrt{x}-\sqrt{y}\right).\dfrac{\sqrt{xy}\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{xy}}\)=x-y

3b)

để A<0 \(\Rightarrow\dfrac{\sqrt{x}-1}{\sqrt{x}}< 0\)

\(\Rightarrow\sqrt{x}-1< 0\)\(\Rightarrow\sqrt{x}< 1\)\(\Rightarrow x< 1\)

=\(\sqrt{\dfrac{1}{100}}-\sqrt{\dfrac{16}{100}}+\sqrt{\dfrac{1}{4}}\)=\(\dfrac{1}{10}-\dfrac{4}{10}+\dfrac{1}{2}\)

=\(\dfrac{-3}{10}+\dfrac{5}{10}=\dfrac{2}{10}=\dfrac{1}{5}\)

=\(\left(x-\sqrt{14}\right)\left(x+\sqrt{14}\right)\)

a)=\(5\sqrt{3}-10\sqrt{3}+4\sqrt{3}=-\sqrt{3}\)

b)=\(7\sqrt{2}+\sqrt{2}-6\sqrt{2}\)=\(2\sqrt{2}\)

c)=\(3\sqrt{2}+8\sqrt{2}-3\sqrt{2}=8\sqrt{2}\)

d)=\(\sqrt{3}-\sqrt{3}+26\sqrt{3}=26\sqrt{3}\)

e)=\(3\sqrt{a}-4\sqrt{a}+7\sqrt{a}=6\sqrt{a}\)

g)=\(4\sqrt{b}+4\sqrt{10b}-9\sqrt{10b}=4\sqrt{b}-5\sqrt{10b}\)

d)=\(\dfrac{\left(7\sqrt{3}-5\sqrt{11}\right)\left(8\sqrt{3}+7\sqrt{11}\right)}{\left(8\sqrt{3}-7\sqrt{11}\right)\left(8\sqrt{3}+7\sqrt{11}\right)}\)

=\(\dfrac{168+49\sqrt{33}-40\sqrt{33}-385}{192-539}\)=\(\dfrac{-217+9\sqrt{33}}{-347}\)

=\(\dfrac{217-9\sqrt{33}}{347}\)

e)=\(\dfrac{\left(3\sqrt{5}-2\sqrt{2}\right)\left(2\sqrt{5}+3\sqrt{2}\right)}{\left(2\sqrt{5}-3\sqrt{2}\right)\left(2\sqrt{5}+3\sqrt{2}\right)}\)

=\(\dfrac{30+9\sqrt{10}-4\sqrt{10}-12}{20-18}\)=\(\dfrac{18+5\sqrt{10}}{2}\)