a) $\dfrac{-13}{7}.\dfrac{16}{35}.\dfrac{7}{-13}=(\dfrac{-13}{7}. \dfrac{7}{-13}).\dfrac{16}{35}=\dfrac{16}{35}$ 

b) $\dfrac{3}{4}.\dfrac{7}{25}+\dfrac{3}{4}.\dfrac{18}{25}=\dfrac{3}{4}.(\dfrac{7}{25}+\dfrac{18}{25})= \dfrac{3}{4}.1=\dfrac{3}{4}$ 

c) $\dfrac{7}{5}.\dfrac{8}{19}+\dfrac{7}{5}.\dfrac{12}{19}-\dfrac{7}{5}.\dfrac{1}{19}=\dfrac{7}{5}.( \dfrac{8}{19}+\dfrac{12}{19}-\dfrac{1}{19})=\dfrac{7}{5}.1=\dfrac{7}{5}$ 

d) $\dfrac{-2}{7}.\dfrac{5}{13}+\dfrac{-2}{7}.\dfrac{8}{13}+1\dfrac{1}{7}=\dfrac{-2}{7}.\dfrac{5}{13}+ \dfrac{-2}{7}.\dfrac{8}{13}+\dfrac{8}{7}=\dfrac{-2}{7}.(\dfrac{5}{13}+\dfrac{8}{13})+\dfrac{8}{7}=\dfrac{-2}{7}.1+\dfrac{8}{7}=\dfrac{6}{7}$ 

Tương Tự

Đáp án:

Giải thích các bước giải:

 a/$\frac{-13}{7}$ ×$\frac{16}{35}$ ×$\frac{7}{-13}$ 

=($\frac{-13}{7}$× $\frac{7}{-13}$ )×$\frac{16}{35}$ 

=$\frac{16}{35}$ 

b/$\frac{3}{4}$ × $\frac{7}{25}$ +$\frac{3}{4}$ × $\frac{18}{25}$ 

=$\frac{3}{4}$ ×($\frac{7}{25}$+$\frac{18}{25}$ )

=$\frac{3}{4}$×1=$\frac{3}{4}$ 

c/$\frac{7}{5}$ × $\frac{8}{19}$ +$\frac{7}{5}$ × $\frac{12}{19}$ -$\frac{7}{5}$ × $\frac{1}{19}$ 

=$\frac{7}{5}$ ×($\frac{8}{19}$ +$\frac{12}{19}$ -$\frac{1}{19}$ )

=$\frac{7}{5}$×1

=$\frac{7}{5}$