II. Find the word which has a different sound in the part underlined. Read the words aloud.(1pt)
1. A. game B .arrange C. skate D. cake
3. A. difficult B. unusual C. uncle D. result
3. A. piano B. fish C. like D. badminton
4. A. rest B. help C. garden D. identify
III. Choose the best option to complete each sentence. Circle A, B, C or D.(1pt)
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2. |
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3. |
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4. |
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1. B
2....
3.C
4.C
......................
1.B
2.C
3.B
4.A
II/ 1.C ; 2.B ; 3.C; 4.D
III/ 1.B; 2.C; 3.B; 4.A
Đặt \(a=\sqrt[3]{16x-24};b=\sqrt[3]{1-3x};c=\sqrt[3]{19x-25}\)
Ta có: \(b^3+c^3=1-3x+19x-25=a^3\)
Ta lại có: \(a=b+c\)
=>\(a^3=\left(b+c\right)^3\)
=>\(a^3=b^3+c^3+3bc\left(b+c\right)\)
\(0=\text{3bc(b+c)}\)
\(0=bc\left(b+c\right)\)
=>\(\orbr{\frac{\begin{cases}c=0\\b=0\end{cases}}{b+c=0}}\)