\(\frac{15-\frac{15}{7}-\frac{15}{2}}{3-\frac{3}{7}-\frac{3}{12}}\)

\(=\frac{15.\left(1-\frac{1}{7}-\frac{1}{2}\right)}{3.\left(1-\frac{1}{7}-\frac{1}{2}\right)}\)mình sửa đề luôn nhé

\(=\frac{15}{3}=5\)

QUÁ DỄ

=5

giải:  12/15(2/7+3/7+1/7+1/7)=12/15.7/7=12/15=4/5

\(=\frac{12}{15}.\left(\frac{2}{7}+\frac{3}{7}+\frac{1}{7}+\frac{1}{7}\right)\)

\(=\frac{12}{15}.1\)

\(=\frac{12}{15}=\frac{4}{5}\)

\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)

\(=\frac{\frac{90}{7}-\frac{15}{12}}{\frac{18}{7}-\frac{3}{12}}\)

\(=\frac{\frac{325}{28}}{\frac{65}{28}}\)

\(=\frac{35}{17}\)

\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)

\(=\frac{\frac{90}{7}-\frac{15}{12}}{\frac{18}{7}-\frac{3}{12}}\)

\(=\frac{\frac{325}{28}}{\frac{65}{28}}\)

\(=5\)

giúp mik với ạ!!!

Câu 2: B

Câu 3: B

Câu 4: A

\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)

= \(\frac{15.\left(1-\frac{1}{7}-\frac{1}{12}\right)}{3.\left(1-\frac{1}{7}-\frac{1}{12}\right)}\)

= \(\frac{15}{3}\)

= 5

=  15/3

=5

15-\(\frac{15}{7}\)-\(\frac{15}{12}\)

3-\(\frac{3}{7}\)-\(\frac{3}{12}\)

=15.[1-\(\frac{1}{7}\)-\(\frac{1}{12}\)]

3.[1-\(\frac{1}{7}\)-\(\frac{1}{12}\)]

=\(\frac{15}{3}\)=5

khó quá mk giải miết mà không ra

khó vãi

a: =-1+17/20=-3/20

b: =(28/60-33/60)*(-25/3)

=(-1/12)*(-25/3)=1/12*25/3=25/36

c: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}=\dfrac{1}{9}\)