\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

= \(\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-1\dfrac{15}{17}\)

= \(1+\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-1\dfrac{15}{17}\)

= \(1+1-1\dfrac{15}{17}\)

= \(2-1\dfrac{15}{17}\)

= \(\dfrac{2}{17}\)

Câu 1:

\(=\dfrac{15}{34}+\dfrac{19}{34}-1-\dfrac{15}{17}+\dfrac{1}{3}+\dfrac{3}{5}\)

\(=-\dfrac{15}{17}+\dfrac{14}{15}=\dfrac{13}{255}\)

Câu 2: 

\(=\dfrac{5^4\cdot5^4\cdot2^8}{4^4\cdot6^4\cdot3^2\cdot5}=\dfrac{5^7}{6^4\cdot3^2}\)

a) - 10                     

=(-7/15.15-7) . (5/8 . -16) 

= 1 . -10 = -10

\(=\frac{3+\frac{3}{4}-\frac{3}{19}}{\frac{5}{2}+\frac{5}{8}-\frac{5}{38}}.\frac{15+\frac{15}{34}+\frac{15}{17}-\frac{15}{144}}{2+\frac{2}{34}+\frac{2}{17}-\frac{2}{144}}+2018\)

\(=\frac{3\left(1+\frac{1}{4}-\frac{1}{19}\right)}{\frac{5}{2}\left(1+\frac{1}{4}-\frac{1}{19}\right)}.\frac{15\left(1+\frac{1}{34}+\frac{1}{17}-\frac{1}{144}\right)}{2\left(1+\frac{1}{34}+\frac{1}{17}-\frac{1}{144}\right)}+2018\)

\(=\frac{3}{\frac{5}{2}}.\frac{15}{2}+2018\)

\(=\frac{6}{5}.\frac{15}{2}+2018\)

\(=9+2018=2027\)

\(\frac{3+0,75-\frac{3}{19}}{\frac{5}{2}+0,625-\frac{5}{38}}\) . \(\frac{15+\frac{15}{17}-\frac{15}{144}+\frac{15}{34}}{2+\frac{2}{17}-\frac{2}{144}+\frac{1}{17}}\)+2018

=\(\frac{3+\frac{3}{4}-\frac{3}{19}}{\frac{5}{2}+\frac{5}{8}-\frac{5}{38}}\) . \(\frac{15+\frac{15}{17}-\frac{15}{144}+\frac{15}{34}}{2+\frac{2}{17}-\frac{2}{144}+\frac{2}{34}}\)+2018

=\(\frac{3\left(1+\frac{1}{4}-\frac{1}{19}\right)}{5\left(\frac{1}{2}+\frac{1}{8}-\frac{1}{38}\right)}\) . \(\frac{15\left(1+\frac{1}{17}-\frac{1}{144}+\frac{1}{34}\right)}{2\left(1+\frac{1}{17}-\frac{1}{144}+\frac{1}{34}\right)}\)+2018

=\(\frac{6\left(\frac{1}{2}+\frac{1}{8}-\frac{1}{38}\right)}{5\left(\frac{1}{2}+\frac{1}{8}-\frac{1}{38}\right)}\) . \(\frac{15\left(1+\frac{1}{17}-\frac{1}{144}+\frac{1}{34}\right)}{2\left(1+\frac{1}{17}-\frac{1}{144}+\frac{1}{34}\right)}\)+2018

=\(\frac{6}{5}\) . \(\frac{15}{2}\)+2018

=9+2018

=2027

Thật ra đề không sai đâu nha các bạn chúng ta cần phân tích để tử số giống mẫu số rồi rút gọn chúng ta sẽ ra được kết quả

Chúc các bạn học tốt

\(\dfrac{15}{34}-\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{15}{17}-\dfrac{2}{3}\)

\(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)-\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-\dfrac{15}{17}\)

\(=1-\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-\dfrac{15}{17}\)

\(=1-1-\dfrac{15}{17}\)

\(=-\dfrac{15}{17}\)

=(15/34+9/34-15/17)+(1/3+2/3)

=(24/34-15/17)+1

=-3/17+1

=14/17