Question

chứng minh rằng: \(\frac{5}{2}=\frac{-5}{-2}\)

Answer 1

Đơn giản: \(\frac{5}{2}=\frac{5.\left(-1\right)}{2.\left(-1\right)}=\frac{-5}{-2}\)

Answer 2

Ta có: \(\frac{5}{2}=\frac{5\left(-1\right)}{2\left(-1\right)}\)

               = \(\frac{-\left(5.1\right)}{-\left(2.1\right)}\)  

               =\(\frac{-5}{-2}\)

Vậy \(\frac{5}{2}=\frac{-5}{-2}\)(đpcm)

Answer 3

5/2=5:(-1)/2:(-1)=-5/-2

=>đpcm

Answer 4

\(\frac{-5}{-2}=\frac{-5:\left(-1\right)}{-2:\left(-1\right)}=\frac{5}{2}\)

Answer 5

ta có \(\frac{a}{b}=\frac{c}{d}<=>a\cdot d=b\cdot c\)

mà : \(5\cdot\left(-2\right)=2\cdot\left(-5\right)\)

\(=>\frac{5}{2}=\frac{-5}{-2}\)