Question

6. a) Rút gọn

i) \(\frac{7.25-49}{7.24+21}\);                    ii) \(\frac{2.\left(-13\right).9.10}{\left(-3\right).4.\left(-5\right).26}\).

b) So sánh hai phân số

i) \(\frac{3}{-4}\) và \(\frac{-1}{-4}\);                       ii) \(\frac{15}{17}\) và \(\frac{25}{27}\).

Answer 1

a) i)\(\frac{7\cdot25-7\cdot7}{7\cdot24+7\cdot3}=\frac{7\left(25-7\right)}{7\left(24+3\right)}=\frac{18}{27}=\frac{2}{3}\) ii)\(\frac{2\cdot\left(-1\right)\cdot13\cdot\left(-3\right)^2\cdot\left(-2\right)\cdot\left(-5\right)}{\left(-3\right)\cdot2\cdot2\cdot\left(-5\right)\cdot13\cdot2}=\frac{-3}{2}\)

b) i)\(\frac{3}{-4}< 0;\frac{-1}{-4}>0=>\frac{3}{-4}< \frac{-1}{-4}\)   

ii) ta có \(\frac{15}{17}+\frac{2}{17}=1;\frac{25}{27}+\frac{2}{27}=1\)

mà \(\frac{2}{17}>\frac{2}{27}\) =>\(\frac{15}{17}< \frac{25}{27}\)

Answer 2

dug ko v

 

Answer 3

chắc chắn