quy đồng nha bạn

8/11 - 3/8 = 64/88 - 33/ 88 = 31/88

ủng hộ nha

8/11 - 3/8 = 31/88

NÈ BẠN!!!

\(\frac{8}{11}-\frac{3}{8}=\frac{64}{88}-\frac{33}{88}=\frac{31}{88}\)

K CHO MK NHA

\(=\dfrac{8}{5}+\dfrac{18+2-14-6}{11}+\dfrac{8}{5}=\dfrac{16}{5}\)

\(8,\\ A=\left\{0;1;2;3\right\}\\ B=\left\{0;1;2\right\}\\ A\cap B=\left\{0;1;2\right\}\\ A\cup B=\left\{0;1;2;3\right\}\\ A\B=\left\{3\right\}\\ B\A=\varnothing\\ 9,\\ A=\left\{0;1;2;3;4\right\}\\ B=\left\{5;6\right\}\\ A\cap B=\varnothing\\ A\cup B=\left\{0;1;2;3;4;5;6\right\}\\ A\B=\left\{0;1;2;3;4\right\}\\ B\A=\left\{5;6\right\}\)

8: \(A\cap B=\left\{3\right\}\)

\(A\cup B\)=(-1;3]

1/2

= (-5/7 + -2/7) + (8/11 + 3/11) + 1/2  = -1 + 1 + 1/2 = 1/2

\(\dfrac{-5}{7}+\dfrac{8}{11}+\left(\dfrac{-2}{7}\right)+\dfrac{1}{2}+\dfrac{3}{11}\\ =\left[\dfrac{-5}{7}+\left(\dfrac{-2}{7}\right)\right]+\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{1}{2}=\left(-1\right)+1+\dfrac{1}{2}=\dfrac{1}{2}\)

\(=\dfrac{11}{4}\cdot\left(-1\right)\cdot\dfrac{8}{33}=\dfrac{2}{3}\cdot\left(-1\right)=-\dfrac{2}{3}\)

\(S=\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{97.100}\)

\(S=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+...+\frac{1}{97}-\frac{1}{100}\right)\)

\(S=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{100}\right)\)

\(S=\frac{1}{3}.\frac{49}{100}\)

\(S=\frac{49}{300}\)

\(s=\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{97.100}\)

\(s=\frac{1}{3}\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-\frac{1}{14}+...+\frac{1}{97}-\frac{1}{100}\right)\)

\(s=\frac{1}{3}\left(\frac{1}{2}-\frac{1}{100}\right)\)

\(s=\frac{1}{3}\left(\frac{50}{100}-\frac{1}{100}\right)\)

\(s=\frac{1}{3}.\frac{49}{100}\)

\(s=\frac{49}{300}\)

Vậy \(s=\frac{49}{100}\)

Chúc bạn học tốt !!!