*Rút gọn :

`(8.5-8.2)/16=(8.(5-2))/(8.2)=(8.3)/(8.2)=3/2`

`(11.4-11)/(2-13)=(11.(4-1))/(-11)=(11.3)/(-1.11)=3/(-1)=-3`

*Quy đồng :

- Ta có : `-3=(-3)/1`

UCLN(2,1)=2

$\to\begin{cases} \dfrac32=\dfrac32\\\dfrac{-3}1=\dfrac{-6}2\end{cases}$

\(\frac{11.4-11}{2-13}=\frac{11\left(4-1\right)}{-11}=\frac{11.3}{-11}=\frac{\left(-11\right).\left(-3\right)}{-11}=-3\)

ket qua la -3

=\(\frac{44-11}{-11}\) 

=\(\frac{33}{-11}\)

=-3

\(\dfrac{-63}{72}=\dfrac{-7}{8}\)

\(\dfrac{20}{-140}=\dfrac{-1}{7}\)

\(\dfrac{3.10}{5.24}=\dfrac{30}{120}=\dfrac{1}{4}\)

\(\dfrac{3.7.11}{22.9}=\dfrac{231}{198}=\dfrac{7}{6}\)

\(\dfrac{8.5-8.2}{16}=\dfrac{24}{16}=\dfrac{3}{2}\)

\(\dfrac{11.4-11}{2-13}=\dfrac{33}{-11}=-3\)

Sử dụng tính chất của phép nhân và phép trừ: rút thừa số chung

a, \(\frac{8.5-8.2}{16}\)\(=\frac{40-16}{16}=\frac{24}{16}=\frac{3}{2}\)

b, \(\frac{11.4-11}{2-13}=\frac{44-11}{-11}=\frac{33}{-11}=-3\)

Chúc em học tốt!

a. \(\dfrac{8,5-8,2}{16}=\dfrac{0,3}{16}=\dfrac{3}{160}\)

b. \(\dfrac{2\cdot14}{7\cdot8}=\dfrac{1\cdot2}{1\cdot4}=\dfrac{2}{4}=\dfrac{1}{2}\)

c. \(\dfrac{11\cdot4-11}{2-13}=\dfrac{11\left(4-1\right)}{-11}=\dfrac{1\cdot3}{-1}=-3\)

d. \(\dfrac{49+7\cdot49}{49}=\dfrac{49\cdot\left(1+7\right)}{49}=\dfrac{8}{1}=8\)

\(\dfrac{72\times75}{125\times108}\) = \(\dfrac{36\times2\times25\times3}{25\times5\times36\times3}\) = \(\dfrac{2}{5}\)