\(a.\dfrac{-25}{16}=-\dfrac{5}{12}.\dfrac{15}{4}\\ b.-\dfrac{25}{16}=-\dfrac{4}{5}:\dfrac{64}{125}\)

a) \(\dfrac{-25}{16}=\dfrac{-5}{12}\cdot\dfrac{15}{4}\)

b) \(\dfrac{-4}{5}:\dfrac{64}{125}=-\dfrac{25}{16}\)

1 , 75 : − 12 ⋅ − 2 3 = 7 4 . − 1 12 . − 2 3 = 7 72

                                                             Giải

a) Ta có : \(\frac{-25}{16}=\frac{-5}{12}.\frac{15}{4}\)

b) Ta có : \(\frac{-25}{16}=\frac{-4}{5}.\frac{64}{125}\)

\(a)\)

\(\frac{-25}{16}=\frac{\left(-5\right).5}{4.4}=\frac{\left(-5\right).5.3}{4.4.3}=\frac{\left(-5\right).15}{12.4}=\frac{\left(-5\right)}{12}.\frac{15}{4}\)

\(b)\)

\(\frac{-25}{16}=\frac{\left(-25\right).4.5}{16.4.5}=\frac{\left(-4\right).25.5}{5.16.4}=\frac{\left(-4\right)}{5}.\frac{125}{64}=\frac{\left(-4\right)}{5}:\frac{64}{125}\)

a) Gọi số cần tìm là: `x`   \(\left(x\in Q;x\ne0\right)\)

Ta có: \(-\dfrac{25}{16}=\dfrac{-5}{12}x\)

`=>` \(x=-\dfrac{25}{16}\div\dfrac{-5}{12}=\dfrac{15}{4}\)

Vậy \(-\dfrac{25}{16}=\dfrac{15}{4}.\dfrac{-5}{12}\).

b) Gọi số cần tìm là: \(y\)   \(\left(y\in Q;y\ne0\right)\)

Ta có: \(-\dfrac{25}{16}=-\dfrac{4}{5}\div y\)

\(\Rightarrow y=-\dfrac{4}{5}\div\dfrac{-25}{16}=\dfrac{64}{125}\)

Vậy \(-\dfrac{25}{16}=-\dfrac{4}{5}\div\dfrac{64}{125}\).

a) Gọi số cần tìm là: x=−2516÷−512=154

Vậy 

−2516=−45÷64125

.

\(a,\dfrac{-3}{35}=\dfrac{-5}{7}\cdot\dfrac{3}{25}\\ b,\dfrac{-3}{35}=\dfrac{-2}{5}:\dfrac{14}{3}\)

a: \(\dfrac{-3}{35}=\dfrac{-5}{7}\cdot\dfrac{3}{25}\)

b: \(-\dfrac{3}{35}=\dfrac{-2}{5}:\dfrac{14}{3}\)

a: −335=−25:143

12. − 2 3 2 = 12. 4 9 = 12.4 9 = 4.4 3 = 16 3 = 5 1 3