ý bạn là như này đúng không vậy
\(\left(17\dfrac{13}{15}-3\dfrac{3}{7}\right)-\left(2\dfrac{12}{15}-4\right)\)
=(268/15-24/7)-(42/15-4)
=(268/15-42/15)+(-24/7+4)
=226/15+4/7
=1642/105
\(\left(17\dfrac{13}{15}-\dfrac{3}{7}\right)-\left(2\dfrac{12}{15}-4\right)\)
=>\(\left(17+\dfrac{13}{15}-\dfrac{3}{7}\right)-\left(2+\dfrac{12}{15}-4\right)\)
=>\(17+\dfrac{13}{15}-\dfrac{3}{7}-2-\dfrac{12}{15}+4\)
=>(17-2+4)+\(\left(\dfrac{13}{15}-\dfrac{12}{15}-\dfrac{3}{7}\right)\)
=>19+\(\dfrac{1}{15}-\dfrac{3}{7}\)=\(19\dfrac{-38}{105}=18\dfrac{105-38}{105}=18\dfrac{67}{105}\)
\(\left(17\dfrac{13}{15}-3\dfrac{3}{7}\right)-\left(2\dfrac{12}{15}-4\right)\)
\(=\left(\dfrac{268}{15}-\dfrac{24}{7}\right)-\left(\dfrac{14}{5}-4\right)\)
\(=\dfrac{1516}{105}-\dfrac{-6}{5}\)
\(=\dfrac{1642}{105}\)
