đang cần gấp chìu nộp cho cô òi ( ai nhanh + đúng = 20 ticksbài 1 tính4.\(\left(\frac{-1}{2}\right)^3-2.\left(\frac{-1}{2}\right)^2+3.\left(\frac{-1}{2}\right)+1\)1bài 2 : tìm xa)\(\frac{37-x}{x+13}=\frac{3}{7}\)b) | x - \(\frac{1}{2}\)| - \(\sqrt{\frac{1}{9}}=\sqrt{\frac{1}{4}}\)c) \(2^{3x+2}=4^{x+5}\)d) \(\frac{3^2.3^8}{27^3}=3^x\)bài 3: tìm x,ya)\(\frac{2x}{3y}=-\frac{1}{3}\)và...
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đang cần gấp chìu nộp cho cô òi ( ai nhanh + đúng = 20 ticks
bài 1 tính
4.\(\left(\frac{-1}{2}\right)^3-2.\left(\frac{-1}{2}\right)^2+3.\left(\frac{-1}{2}\right)+1\)1
bài 2 : tìm x
a)\(\frac{37-x}{x+13}=\frac{3}{7}\)
b) | x - \(\frac{1}{2}\)| - \(\sqrt{\frac{1}{9}}=\sqrt{\frac{1}{4}}\)
c) \(2^{3x+2}=4^{x+5}\)
d) \(\frac{3^2.3^8}{27^3}=3^x\)
bài 3: tìm x,y
a)\(\frac{2x}{3y}=-\frac{1}{3}\)và -2x+3y=7
Bài 1:
\(4.\left(\frac{-1}{2}\right)^2-2.\left(\frac{-1}{2}\right)^2+3.\left(\frac{-1}{2}\right)+1\)
\(=4.\frac{1}{4}-2.\frac{1}{4}+3.\left(\frac{-1}{2}\right)+1\)
\(=1-\frac{1}{2}-\frac{3}{2}+1\)
\(=0\)
Bài 2:
a) \(\frac{37-x}{x+13}=\frac{3}{7}\)
\(\Rightarrow7\left(37-x\right)=3\left(x+13\right)\)
\(\Rightarrow259-7x=3x+39\)
\(\Rightarrow259-39=3x+7x\)
\(\Rightarrow220=10x\)
\(\Rightarrow x=22\)
d) \(\frac{3^2.3^8}{27^3}=3^x\)
\(\Rightarrow\frac{3^{10}}{\left(3^3\right)^3}=3^x\)
\(\frac{\Rightarrow3^{10}}{3^9}=3^x\)
\(\Rightarrow3=3^x\)
\(\Rightarrow x=1\)
Hok tốt nha^^