xin lỗi mk sai

sửa lại:

\(\dfrac{2}{3}+\dfrac{1}{3}.\dfrac{-6}{10}=\dfrac{20}{30}+\dfrac{-6}{30}=\dfrac{14}{30}=\dfrac{7}{15}\)

\(\Rightarrow\)đáp án đúng là B

ps:xin lỗi các bạn mk nhầm

ta có:\(\dfrac{2}{3}+\dfrac{1}{3}.\dfrac{-6}{10}=1.\dfrac{-6}{10}=\dfrac{-6}{10}\)

\(\Rightarrow\)đáp án đúng là A

\(\frac{2^{4+6}}{2^{5.2}}-\frac{2^5.3^3.5^3}{2^3.3^3.2^2.5^2}=\frac{2^{10}}{2^{10}}-\frac{2^5.3^3.5^3}{2^5.3^3.5^2}=1-5=-4\)

bn hoc gioi thiet

a) \(\frac{-2}{5}+\frac{3}{10}+\frac{-3}{5}\)

\(=\left[\left(-\frac{2}{5}\right)+\left(-\frac{3}{5}\right)\right]+\frac{3}{10}\)

\(=\left(-1\right)+\frac{3}{10}\)

\(=-\frac{7}{10}.\)

c) \(15\frac{1}{4}:\frac{5}{7}-25\frac{1}{4}:\frac{5}{7}\)

\(=\frac{61}{4}:\frac{5}{7}-\frac{101}{4}:\frac{5}{7}\)

\(=\left(\frac{61}{4}-\frac{101}{4}\right):\frac{5}{7}\)

\(=\left(-10\right):\frac{5}{7}\)

\(=-14.\)

Chúc bạn học tốt!

a, \(A=\dfrac{10^{15}+1}{10^6+1}>1\);\(B=\dfrac{10^6+1}{10^{17}+1}< 1\)

⇒\(A>B\)

b, \(D=\dfrac{2^{2007}+3}{2^{2006}-1}=\dfrac{2^{2008}+6}{2^{2007}-2}\)

Ta có : \(\dfrac{2^{2008}-3}{2^{2007}-1}< \dfrac{2^{2008}-3}{2^{2007}-2}< \dfrac{2^{2008}+6}{2^{2007}-2}\)

⇒ \(C< D\)

c, \(M=\dfrac{3}{8^3}+\dfrac{7}{8^4}=\dfrac{3}{8^3}+\dfrac{3}{8^4}+\dfrac{4}{8^4}\)

\(N=\dfrac{7}{8^3}+\dfrac{3}{8^4}=\dfrac{3}{8^3}+\dfrac{4}{8^3}+\dfrac{3}{8^4}\)

Vì \(\dfrac{4}{8^4}< \dfrac{4}{8^3}\)

⇒ \(M< N\)

a: \(A=\dfrac{2^{12}\cdot3^{10}+2^3\cdot2^9\cdot3^9\cdot3\cdot5}{2^{12}\cdot3^{12}+2^{11}\cdot3^{11}}\)

\(=\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{11}\cdot3^{11}\cdot7}\)

\(=\dfrac{2^{12}\cdot3^{10}\cdot6}{2^{11}\cdot3^{11}\cdot7}=\dfrac{2}{3}\cdot\dfrac{6}{7}=\dfrac{12}{21}=\dfrac{4}{7}\)

b: \(B=\left(\dfrac{12}{105}+\dfrac{9^{15}}{3}\right)\cdot\dfrac{1}{3}\cdot\dfrac{6^8}{6^4\cdot2^4}\)

\(=\dfrac{12+35\cdot9^{15}}{105}\cdot\dfrac{1}{3}\cdot3^4\)

\(=\dfrac{12+35\cdot9^{15}}{105}\cdot3^3=\dfrac{9\left(12+35\cdot9^{15}\right)}{35}\)

bạn ơi ! đề bài

a) Vì |x-2| \(\ge\)0(1)

(2y-3)^10\(\ge\)0(2)

Từ (1),(2)\(\Rightarrow\)|x-2|+(2y-3)^10 +15\(\ge\)15

Dấu "=" xảy ra \(\Leftrightarrow\) x-2=0

2y-3=0

\(\Leftrightarrow\)x=2

y=3/2

Vậy GTNN của A=15\(\Leftrightarrow\)x=2;y=3/2

thanks bạn