Câu a:

(4\(\frac{5}{37}\) - 3\(\frac45\) + 8\(\frac{15}{29}\)) - (3\(\frac{5}{37}\) - 6\(\frac{14}{29}\))

= 4\(\frac{5}{37}\) - 3\(\frac45\) + 8\(\frac{15}{29}\) - 3\(\frac{15}{37}\) + 6\(\frac{14}{29}\)

= (4 - 3) + (\(\frac{5}{37}-\frac{5}{37}\)) + (8 + 6) + (\(\frac{15}{29}\) + \(\frac{14}{29}\)) - 3 - \(\frac45\)

= 1 + 0 + 14 + 1 - 3 - \(\frac45\)

= 1 + 14 + 1 - 3 - \(\frac45\)

= 15 + 1 - 3 - \(\frac45\)

= 16 - 3 - \(\frac45\)

= 13 - \(\frac45\)

= \(\frac{61}{5}\)

Bài 2:

- \(\frac75\) + \(x\) = - \(\frac34\)

\(x\) = - \(\frac34+\frac75\)

\(x=-\frac{15}{20}\) + \(\frac{28}{20}\)

\(x\) = \(\frac{13}{20}\)

Vậy \(x=\frac{13}{20}\)

Bài 3:

- \(\frac74\) + \(\frac14:x\) = \(\frac32\)

\(\frac14:x\) = \(\frac32+\frac74\)

\(\frac14:x\) = \(\frac64+\frac74\)

\(\frac14:x=\frac{13}{4}\)

\(x=\frac14:\frac{13}{4}\)

\(x=\frac14\times\frac{4}{13}\)

\(x=\frac{1}{13}\)

Vậy \(x=\frac{1}{13}\)

\(\frac{37-x}{x+13}=\frac{3}{7}\)

\(\Leftrightarrow3.\left(x+13\right)=7.\left(37-x\right)\)

\(\Leftrightarrow3.x+13.3=7.37-7.x\)

\(\Leftrightarrow3x+39=-7x+259\)

\(\Leftrightarrow3x+7x=259-39\)

\(\Leftrightarrow10x=220\)

\(\Leftrightarrow x=22\)

$\frac{37-x}{x+13}=\frac{3}{7}$

\(\frac{4}{7}=\frac{7}{x^2}\)

\(\Leftrightarrow4x^2=7.7\)

\(\Leftrightarrow\left(2x\right)^2=49\)

\(\Leftrightarrow\orbr{\begin{cases}2x=7\\2x=-7\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{7}{2}\end{cases}}\)

\(\frac{37-x}{x+13}=\frac{3}{7}\)

\(\Leftrightarrow\left(37-x\right).7=3.\left(x+13\right)\)

\(\Leftrightarrow259-7x=3x+39\)

\(\Leftrightarrow10x=220\)

\(\Leftrightarrow x=22\)

Vậy ... 

Bài còn lại tương tự 

quá dễ luôn, nhân chéo đi

a, <=> 7(37-x)=3(x+13)

<=> x =22

b, <=> (x+1)(x-1)=15

<=> x^2-1=15 <=> x^2=16 <=> x= +_4

\(\Leftrightarrow7\left(37-x\right)=3\left(x+13\right)\Leftrightarrow259-7x=3x+39\Leftrightarrow259-39=3x+7x\)

\(10x=220\Leftrightarrow x=22\)

(37-x) . 7 =3. (x+13)

=>259 -7x=3x+39

=>.259-39=3x+7x

=>220=10x

=>x=22

\(\frac{37-x}{x+13}=\frac{3}{7}\)

=> 3.(x+13)=7.(37-x)

=> 3x+39= 259-7x

=> 3x+7x=259-39

=> 10x= 220

=> x=22

\(\frac{a}{b}\) ai bày mk viết phân số với