Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.

A. killed

B. cured

C. crashed

D. waived

Hình bạn tự vẽ nha

Trên tia PI lấy Q sao cho PI = QI
Xét ΔMIQ và ΔNIP có :
PI = QI ( cách vẽ )
​MIQ​^​​=​NIQ​^​​ ( đối đỉnh )
MI = IN ( giả thiết )
\(\Rightarrow\)ΔMIQ=ΔNIP ( c.g.c)
\(\Rightarrow\)PN = MQ (2 cạnh tương ứng)
Áp dụng bất đẳng thức trong tam giác với ΔMPQ . Ta có :
MP+MQ>>PQ
\(\Rightarrow\)PM+PN>PI+QI
\(\Rightarrow\) PM+PN>2PI

\(\dfrac{1}{99.97}-\dfrac{1}{97.95}-\dfrac{1}{95.93}-...-\dfrac{1}{5.3}-\dfrac{1}{3.1}\)

=\(\dfrac{1}{99.97}-\)(\(\dfrac{1}{97.95}+\dfrac{1}{95.93}+...+\dfrac{1}{5.3}+\dfrac{1}{3.1}\))

=\(\dfrac{1}{99.97}-\)\(\dfrac{1}{2}\left(\dfrac{1}{95}-\dfrac{1}{97}+\dfrac{1}{93}-\dfrac{1}{95}+\dfrac{1}{3}-\dfrac{1}{5}+1-\dfrac{1}{3}\right)\)

=\(\dfrac{1}{99.97}-\dfrac{1}{2}\left(1-\dfrac{1}{97}\right)\)

=\(\dfrac{1}{99.97}-\dfrac{1}{2}.\dfrac{96}{97}\)

=\(\dfrac{1}{99.97}-\dfrac{48}{97}\)

=\(\dfrac{1}{99.97}-\dfrac{48.99}{99.97}\)

=\(\dfrac{-4751}{9603}\)