a ) 3^3 x 9^ -1 b) 25 x 5 ^ -1 x 1 c ) 3^2 x 1/243 x (81)^2 x 3^ -3 d ) 3^2 x 2^ 5 x ( 3/2 )^ - 2 Good luck ! :)
2 câu trả lời
\[\begin{array}{l} a)\,\,\,{3^3}{.9^{ - 1}} = 27.\frac{1}{9} = 3.\\ b)\,\,\,{25.5^{ - 1}}.1 = \frac{{25}}{5} = 5.\\ c)\,\,{3^2}.\frac{1}{{243}}{.81^2}{.3^{ - 3}} = \frac{{{3^2}}}{{{3^5}}}.{\left( {{3^4}} \right)^2}{.3^{ - 3}} = \frac{1}{{{3^3}}}{.3^8}.\frac{1}{{{3^3}}} = \frac{{{3^8}}}{{{3^6}}} = {3^2} = 9.\\ d)\,\,{3^2}{.2^5}.{\left( {\frac{3}{2}} \right)^{ - 2}} = {3^2}{.2^5}.{\left( {\frac{2}{3}} \right)^2} = \frac{{{3^2}{{.2}^5}{{.2}^2}}}{{{3^2}}} = {2^7}. \end{array}\]
Đáp án:
Giải thích các bước giải: a) 27 x 1/9 = 3
b) 25 x 1/5 x 1 = 5
c) 9 x 1/243 x 6561 x 1/27
d) 9 x 32 x 4/9 = 128
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