a. 411 : 210 : 211= 222 : 210:211= 222-10-11= 2
b. \(\dfrac{11.2^{11^{ }}-10.4^5}{16^3}\)=\(\dfrac{11.2^{11}-10.2^{10}}{2^{12}}\)= \(\dfrac{2^{10^{ }}\left(2.11-10\right)}{2^{12}}\)=3
c.(25 +14.24) : 23= (25+2.7.24) :23= (25.(1+7) :23= 25 = 32
d. A = 12.(\(\dfrac{-2}{3}\))2+\(\dfrac{4}{3}\)= 12.\(\dfrac{4}{9}\) + \(\dfrac{4}{3}\) = \(\dfrac{16}{3}\)+\(\dfrac{4}{3}\)=\(\dfrac{20}{3}\)
1: Tính hợp lí:
a, \(\dfrac{11}{125}\)- \(\dfrac{17}{18}-\dfrac{5}{7}+\dfrac{4}{9}\)+ \(\dfrac{17}{14}\)
b,\(-1\dfrac{5}{7}.15+\dfrac{2}{7}.\left(-15\right)+\left(-105\right).\left(\dfrac{2}{3}-\dfrac{4}{5}+\dfrac{1}{7}\right)\)
2: Tìm x:
a, \(\dfrac{11}{13}-\left(\dfrac{5}{42}-x\right)=-\left(\dfrac{15}{28}-\dfrac{11}{13}\right)\)
b,\(|x+\dfrac{4}{15}|-|-3,75|=-|-2,15|\)
c, \(^{7^{x+2}}+2.7^{x-1}=345\)
Tìm x:
a/\(\left(\dfrac{12}{25}\right)^x\)=\(\left(\dfrac{3}{5}\right)^2-\left(-\dfrac{3}{5}\right)^4\)
b/\(\left(-\dfrac{3}{4}\right)^{3x-1}=\dfrac{256}{81}\)
c/172\(x^2-7^9:98^3=2^{-3}\)
Viết dưới dạng lũy thừa của một số nguyên:
a/\(12^3:\left(3^{-4}.64\right)\)
b/\(\left(\dfrac{3}{7}\right)^5.\left(\dfrac{7}{3}\right)^{-1}.\left(\dfrac{5}{3}\right)^6:\left(\dfrac{343}{625}\right)^{-2}\)
c/\(5^4.125.\left(2,5\right)^{-5}.0,04\)
Tìm x:
\(\dfrac{x}{-18}=\dfrac{-50}{x};\\ 1\dfrac{1}{3}:\left(-0,08\right)=\dfrac{2}{3}:\left(-0,1x\right);\\ x=\dfrac{a}{b+c}=\dfrac{b}{c+a}=\dfrac{c}{b+a};\\ \dfrac{x^2}{6}=\dfrac{24}{25};\dfrac{x+1}{x-5}=\dfrac{0,5}{0,6};\\ \dfrac{2}{3}x:\dfrac{1}{5}=1\dfrac{1}{3}:\dfrac{1}{4};\\ 1,35:0,2=1,25:0,1x\)
Tìm \(x\in Z\),biết:
a/\(x^2=16\)
b/\(x^3=-8\)
c/\(\left(x+2\right)^2=4\)
d/\(\left(1-x\right)^3=1\)
e/\(\dfrac{1}{4}.\dfrac{1}{6}.\dfrac{3}{8}.\dfrac{4}{10}.....\dfrac{14}{30}.\dfrac{15}{32}=2^x\)
So sánh A=\(\left(ax+by\right)^2\)và B=\(\left(a^2+b^2\right)\left(x^2+y^2\right)\) biết rằng a=2,b=-1;x=\(\dfrac{8}{11}\):y=\(-\dfrac{5}{11}\)
Tìm x,y:
a/\(x^2+\left(y-\dfrac{1}{10}\right)^4=0\)
b/\(\left(\dfrac{1}{2}x-5\right)^{20}+\left(y^2-\dfrac{1}{4}\right)^{10}\le0\)
Tìm x:
a/\(\left(5x+1\right)^2=\dfrac{36}{49}\)
b/\(\left(x-\dfrac{2}{9}\right)^3=\left(\dfrac{2}{3}\right)^6\)
c/\(\left(8x+1\right)^{2n+1}=5^{2n+1}\left(n\in N\right)\)
Tìm x thuộc N biết rằng:
a/\(8< 2^x\)bé bằng\(2^6.2^{-2}\)
b/\(\left(\dfrac{2}{5}\right)^x>\left(\dfrac{5}{2}\right)^{-3}.\left(-\dfrac{2}{5}\right)^2\)
