câu hỏi như này hà phương  à

72 phần 45 bằng 8 phần ....

đây là rút gọn phân số

dễ vậy 72/45=8/5

bảy hai phần bốn lăm = tám phần năm

\(\frac{x}{8}=\frac{-15}{30}\)

\(\Rightarrow x=\frac{-15.8}{30}\)

\(\Rightarrow x=-4\)

\(\frac{y}{6}=\frac{15}{-45}\)

\(\Rightarrow y=\frac{15.6}{-45}\)

\(\Rightarrow y=-2\)

A)           \(\frac{x}{8}=\frac{-15}{30}\)

\(\Leftrightarrow\)\(x=\frac{\left(-15\right).8}{30}=-4\)

Vậy...

B)    \(\frac{y}{6}=\frac{15}{-45}\)

\(\Leftrightarrow\)\(y=\frac{15.6}{-45}=-2\)

Vậy....

\(\dfrac{63}{27}=\dfrac{7}{3}\)

\(\dfrac{3\times4\times6}{12\times8\times5}=\dfrac{3\times1\times1}{1\times1\times5}=\dfrac{3}{5}\)

\(A=\dfrac{1+2+...+9}{11+12+...+19}=\dfrac{\left(9+1\right)\times9:2}{\left(19+11\right)\times9:2}=\dfrac{45}{135}=\dfrac{1}{3}\)

143/132=1,083

3535/3737=0,945

ko dư nha

\(\frac{143}{132}=\frac{13}{12}\)

\(\frac{3535}{3737}=\frac{35}{37}\)

`27/81=(27:27)/(81:27)=1/3`

`57/76=(57:19)/(76:19)=3/4`

`35/84=(35:7)/(84:7)=5/12`

`MSC:12`

`1/3=(1xx4)/(3xx4)=4/12`

`3/4=(3xx3)/(4xx3)=9/12`

`5/12` giữ nguyên

\(\dfrac{27}{81}=\dfrac{1}{3}\); \(\dfrac{57}{76}=\dfrac{3}{4}\); \(\dfrac{35}{84}=\dfrac{5}{12}\)

\(\dfrac{1}{3}=\dfrac{4}{12}\)

\(\dfrac{3}{4}=\dfrac{9}{12}\)

Giữa nguyên 5/12

\(\dfrac{12}{60}=\dfrac{12:12}{60:12}=\dfrac{1}{5}\)

\(\dfrac{12:12}{60:12}=\dfrac{1}{5}\)

\(\dfrac{12}{60}=\dfrac{12:12}{60:12}=\dfrac{1}{5}\)

1: Rút gọn

a) \(-\dfrac{33}{51}=\dfrac{-33:3}{51:3}=\dfrac{-11}{17}\)

b) \(\dfrac{156}{-168}=\dfrac{-156}{168}=\dfrac{-156:12}{168:12}=\dfrac{-13}{14}\)

c) \(\dfrac{-75}{-100}=\dfrac{75}{100}=\dfrac{75:25}{100:25}=\dfrac{3}{4}\)

2: Quy đồng mẫu:

a) \(-\dfrac{3}{8}\) và \(\dfrac{5}{4}\)

MSC: 8

\(-\dfrac{3}{8}=\dfrac{-3}{8}\)

\(\dfrac{5}{4}=\dfrac{5\cdot2}{4\cdot2}=\dfrac{10}{8}\)

b) \(\dfrac{-7}{6}\) ; \(\dfrac{5}{12}\) và \(-\dfrac{5}{6}\)

MSC: 12

\(-\dfrac{7}{6}=\dfrac{-7\cdot2}{6\cdot2}=\dfrac{-14}{12}\)

\(\dfrac{5}{12}=\dfrac{5}{12}\)

\(\dfrac{-5}{6}=\dfrac{-5\cdot2}{6\cdot2}=\dfrac{-10}{12}\)

bó tay

5 phần 20 với 25 phần 100 với 8 phần 32 đúng không ??

Đúng thì tk nha

5/20 = 25/ 100